What Everyone (Especially Vegetarians) Should Know About B12 Deficiency

b12 deficiencyIn May of 2011, I wrote an article called B12 Deficiency: A Silent Epidemic With Serious Consequences. I argued that B12 deficiency is much more common than statistics indicate, with potentially devastating consequences. B12 deficiency can cause or is associated with:

  • Premature aging
  • Neurological disorders similar in presentation to multiple sclerosis
  • Brain fog, memory problems and cognitive decline
  • Stroke, heart disease and other vascular problems (due to elevated homocysteine)
  • Developmental or learning disabilities in children
  • Impaired immune function, autoimmune disease and cancer
  • Male and female infertility
  • Numerous other symptoms…

One of the biggest problems with diagnosing B12 deficiency is that the conventional serum B12 test that most doctors run only picks up a small fraction of people who are actually B12 deficient. This test measures the total amount of B12 in the blood, and does not rule out functional B12 deficiency. (1) More sensitive markers for B12 deficiency are now available, including methylmalonic acid (MMA) and holotranscobalamin II (holo-TC). MMA is converted to succinic acid via an active-B12 dependent enzyme, so if MMA levels are high, it suggests that active B12 is lacking. Holotranscobalamin II is composed of vitamin B12 attached to transcobalamin, and it represents the biologically active part of B12 that can actually be delivered to the cells and perform all of the functions of B12. Studies using these newer methods report much higher levels of deficiency than studies using only serum B12.

For example, a one review using serum B12 indicated that 52% of vegans and 7% of vegetarians are B12 deficient. (2) But a study using the more sensitive techniques found much higher rates of deficiency: 68% for vegetarians and 83% of vegans, compared to just 5% of omnivores. (3) That’s a huge, game-changing difference. It means that conventional testing is missing 61% of vegetarians and 31% of vegans that are B12 deficient. This is especially important because B-12 depletion can take years to become clinically evident (i.e. deficiency sets in long before obvious symptoms appear), and some of the more serious effects of B12 deficiency (such as nerve damage) are irreversible.

The effects of B12 deficiency can be irreversible—but most who are deficient don’t know it.Tweet This

Although rates of B12 deficiency are much higher in vegetarians and vegans than in omnivores, that doesn’t mean it’s rare in omnivores. According to the study above, approximately 1 in 20 omnivores are B12 deficient. In my practice I’d estimate the rate at closer to 1 in 15, possibly because I see a lot of people with gut problems and that is one of the risk factors for B12 deficiency. Other risk factors include age (people 60 or older), present or past use of acid-suppressing drugs or other medications like metformin and women with a history of miscarriage and infertility.

Frankly, I’m amazed that this very serious problem doesn’t get more attention in the media. As Sally Pacholok and Jeffrey Stuart point out in their book Could It Be B12: An Epidemic of Misdiagnoses:

Over-diagnosis of B12 deficiency is essentially innocuous [because B12 is so safe to supplement with]; but…’missed diagnosis is quite clearly a matter of great gravity, particularly since the risk of formidable devastation from neurologic damage that results from uncorrected cobalamin deficiency is preventable.’

The importance of early diagnosis

Researchers now recognize four categories of B12 deficiency:

  • Stage I & II: plasma and cell stores of B12 become depleted and the concentration of holotranscobalamin II is reduced.
  • Stage III: functional B12 imbalance characterized by elevated homocysteine and urinary MMA concentrations in the blood.
  • Stage IV: clinical signs of B12 deficiency become evident. (3)

As you can see, signs like macrocytic anemia and symptoms like peripheral neuropathy or brain fog do not appear until the final stage of B12 deficiency. By then, in the case of the neurological symptoms, it may be too late to reverse them. This makes early diagnosis crucial.

Of all of the available markers I mentioned above, holo-TC is considered to be the most sensitive. It can detect B12 deficiency in Stages I & II, whereas urinary MMA and homocysteine typically don’t become elevated until Stage III. Unfortunately, holo-TC is not yet widely available. Quest Diagnostics has recently begun to offer it, though, and it is one of the largest national laboratories so your doctor should be able to order it if you ask. [Update: although Quest lists it on their website, they apparently do not offer it at any Quest location in US as of 1-18-13.]

There are two ways to have MMA measured: in the serum, and in the urine. (4) Each has advantages and disadvantages. Some experts believe that urinary MMA is superior to serum MMA as a marker — possibly because it is more concentrated in the urine than the blood. However, elevations in urinary MMA can also be caused by kidney dysfunction. (5, 6) On the other hand, serum MMA can be elevated in the presence of intestinal bacterial overgrowth. (7). Therefore, which test you choose should depend on your health status. If there’s any question of impaired kidney function, serum MMA would be a better choice. If you have or think you may have SIBO or gut dysbiosis, urinary MMA would be the better choice. Quest, Labcorp and many other labs offer both serum or urniary MMA, so you shouldn’t have any problem getting it provided your doctor will order it. Note that you need to be fasting for the urinary MMA to get an accurate result.

If you can’t get either of these tests, you can order the standard serum B12 test yourself from DirectLabs.com or through your doctor. However, in that case you need to use a different range than what the lab provides. Although most labs define deficiency at <200 pg/mL, it is well documented that many people experience signs and symptoms of B12 deficiency at levels between 200 pg/mL and 350 pg/mL. (8) Also, be aware that a high serum B12 does not necessarily rule out functional/active B12 deficiency. In fact, I have come to view a high serum B12 in the absence of supplementation as a potential red flag for active B12 deficiency.

If you suspect you have B12 deficiency

The first step is to get a holo-TC and/or urinary MMA test. If either of them are abnormal, you should immediately take steps to increase your B12 levels. There are two ways to do this:

  1. Eat B12-rich foods.
  2. Supplement.

B12 in the diet

B12 is the only vitamin that contains a trace element (cobalt), which is why it’s called cobalamin. Cobalamin is produced in the gut of animals. It’s the only vitamin we can’t obtain from plants or sunlight. Plants don’t need B12 so they don’t store it. B12 is found exclusively in animal foods, such as liver, clams, oysters, mussels, fish eggs, octopus, fish, crab and lobster, beef, lamb, cheese and eggs.

A common myth amongst vegetarians and vegans is that it’s possible to get B12 from plant sources like seaweed, fermented soy, spirulina and brewers yeast. But plant foods said to contain B12 actually contain B12 analogs called cobamides that block intake of and increase the need for true B12. (9) My intention here is not to bash vegetarian and vegan diets (I was a macrobiotic vegan myself at one point, for crying out loud!). I recognize that there are many reasons why people choose to eat the way they do, and I respect people’s right to make their own choices. I also know that, like all parents, vegetarians and vegans want the best for their children. This is why it’s crucial for those that abstain from animal products to understand that there are no plant sources of B12 and that all vegans and most vegetarians should supplement. This is especially important for vegetarian or vegan children or pregnant women, whose need for B12 is even greater than adults. In addition, omnivores that are low in B12 despite eating a diet rich in animal foods that contain B12 should also supplement.

Supplementing with B12

Cyanaocobalamin is the most frequently used form of B12 supplementation in the US. But recent evidence suggests that hydroxycobalamin (frequently used in Europe) is superior to cyanocobalamin, and methylcobalamin may be superior to both – especially for neurological disease. (9, 10 p. 225) This is probably because methylcobalamin bypasses several problems in the B12 absorption cycle and doesn’t need to be decyanated or reduced to the (+1) state (the only state that can cross the blood-brain barrier). On top of that, methylcobalamin provides the body with methyl groups that play a role in various biological processes important to overall health.

A general approach to B12 supplementation might include  1,000 mcg (1 mg) of sublingual methylcobalamin — Jarrow Formulas Methyl-B12 is a good choice — along with co-factors like folate (Solgar Folate 800 Mcg 1x/d), potassium (Natures Way Potassium 99mg 3x/d) and trimethylglycine/TMG (Jarrow 500mg 1x/d).

Note: I earn a small commission if you use the links in this article to purchase the products I mentioned. I only recommend products I would use myself or that I use with patients in my practice. Your purchase helps support this site and my ongoing research.

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Comments Join the Conversation

  1. Susan says

    I just had a regular serum B-12 test and it came back high. 1296
    I had been taking a B complex supplement that had 250 mg of B-12 in a time release formula. I don’t go back to my doctor for a couple weeks yet. Since B-12 is water soluble, what would cause such a high number? The reference range given was 132-653 pg/ml

  2. Charlotte says

    Has anyone heard of Eligen B12? Apparently it’s a new prescription oral tablet I recently read about that works as well as the IM B12 injection, even if you don’t have intrinsic factor. I think it came out a month or two ago

  3. ally says

    Hi chris- is it safe to start methyl b12 and methyl folate while breastfeeding? I’m worried about the release of toxins. Thank you!

  4. Claire Bear says


    I have been vegan for nearly 3 years, but stupidly, I was not taking a B12 supplement regularly, and when I was it was just a low dose supermarket brand.

    I have symptoms of low B12; tingling on my lips and tongue, a sore mouth, pins and needles in my hands and feet, it is almost constant in my fingertips. I have experienced weakness, especially in my legs. I have been unable to concentrate on my studies, my memory is poor, I sometimes feel confused and spaced out. I have anxiety (and depression) anyway, but the anxiety as been through the roof for the past 3-4 months. I am in a constant state of feeling anxious.

    I requested a blood test from my Doctor, and started taking 50 mcg of hydroxycobalamin for nearly 2 weeks before I could get an appointment for my test. I have just received the results, which were 479. I am not sure what this means but it was done through the NHS. I have read that under 200 is a deficiency, so I was relieved not to have to have B12 injections, as I have a needle phobia.

    I also read that you should not experience symptoms under 400, I am still experiencing these symptoms, and I am now wondering if I should not have taken the B12 supplements before my blood test.

    I have purchased 1000 mcg of methylcobalamin, but I am yet to take them because I am anxious that I will have an allergic reaction to them.

    I have never been anxious to take supplements before, but now my anxiety is so bad that I am worrying about every little thing.

    Could you please tell me if the supplements could have given me a false reading.

    Thank you in advance.

    Kind regards,


    • Ann says

      I started on methylcobalamin and upped my B12 from 200 to over 1000. I also tested for other deficiencies and found out I was low in B1, B2, D3, iron, Vitamin C, iodine, MMA and anemic. I am taking supplements to bring all the deficiencies up to level. Will have blood checked again next month, but feel 100% better than I did months ago.

      Check for other deficiencies, not just the B12.

  5. says

    5% of meat eaters are deficent? What rubbish. Anyone who buys meat from supermarkets will be deficient. It’s a common myth you can only get b 12 from animals and animal products. Complete lies. Supermarket meat has no b 12 and any meat you buy which has b 12 won’t unless you eat it raw because heat kills b12. An easyish way to get b 12 is to grow your own fruit and veg and not wash it to the dirt has b 12 in it. It’s a lesser known fact but it’s true.

  6. Sandi says

    Hi Chris im from adelaide, australia and i suffer with pancreatitis and under active thyroid i have had my B12 tested and its normal and i was wandering if i can still take the sublingual B12

    • Margaret McCarthy says

      I am having symptoms and wanted to trial therapeutic B12 injections. My GP has said no. I don’t want to pay privately as this is a rip off.

  7. LoriB12 says

    This B12 thing is completely new to me. About 3 weeks ago, I woke up one day with slightly blurred vision. The next day I had the blurred vision and a weird taste in my mouth. The 3rd day, I still had blurred vision, weird taste, and my left arm was tingling, I went to Urgent Care and they did a CT scan just to be sure I didn’t have a stroke or something. The following week, my MD ordered a complete blood count and my B12 was 230. I started weekly injections (I’ve had 4 so far) and I also went to a Neurologist. He ordered a contrasted and non-contrasted MRI to check for anything and rule out things. MRI came back clear. To date, my hands and feet are numb/tingly, my toes feel like icicles, my hands feel like fireballs, my hands are very sensitive at the moment to cold, my taste is still off as my tongue feels numb, and I have some shortness of breath. I’m wondering if the symptoms I am currently feeling will be 100% reversible since it appears to have only started within the last month. Also, just for my own peace of mind, how long this reversal would generally take?

  8. Tracy says

    “As you can see, signs like macrocytic anemia and symptoms like peripheral neuropathy or brain fog do not appear until the final stage of B12 deficiency.”

    This paragraph stood out as I’ve had vitamin B12 malabsorption for since I was a small child (have juvenile autoimmune pernicious anaemia which was slowly progressing and I diagnosed myself at age 35) and symptoms from enlarged pupils and signs of cranial nerve damage to severe brain fog for decades.

    When my vitamin B12 serum went well below the reference range, my blood cells still didn’t enlarge. I had masked anaemia possibly due to high folate in my diet or chronic inflammation.

  9. says

    Thanks for the article. I was advised by my doctors for a Vitamin b 12 sublingual supplement post my bariatric bypass surgery. The sublingual form is the fastest way of absorbing the vitamin as the capsule breaks down and releases them directly into the blood stream, maximum effect through absorption.

  10. Caroline says

    I can’t find any information of whether or not it is safe to exercise while having low B-12 levels. After months of feeling very tired, weak and overwhelmed (and having some shooting pains in my ankle, which I attributed to running too much), I had a blood test done last week which showed that my B-12 level is 195. My doctor did not seem to be particularly concerned about it, and suggested supplements and eating B12 rich foods to see if that will bring the levels up. Would it be beneficial to stop exercising until I am feeling better or can/should I continue to ‘tough it out’?

  11. Penelope says

    I am not a vegetarian nor have I ever been. However I do have some gastro issues. Once a diagnosis was made I was given a treatment of B12 Hydroxocobalamin 1000 over 2 weeks then placed onto a maintenance dose of 1 injection every 3 months.

    The maintenance dosage level was inadequate as I found the last month of every third month a wipe out in regards to effectiveness.

    Over time I reviewed my personal experience and was determined to communicate this to a GP and I am now the maximum treatment permissible by NICE guidelines of 1 injection per 8 weeks on a regular basis equal to PA.

    I takes 2 weeks to kick in once I have the injection and find myself in a position of experiencing a premium 2 week window whereupon the effect gradually diminishes as time goes by, leaving me frustrated and fairly tired more and more as time progresses through this (now regular) 8 week cycle.

    Can anyone tell me do they or have they experienced this type of experience?

    Can someone also tell me the difference between the various cobalamin options out there as I believe there are three main types.

  12. Josh says

    People should go to VeganReport.com to get a full report on how they can supplement their diet with non-vegan sources, in a vegan manner.

  13. Penelope says

    I am very new at this as this is my first time I am trying to post.

    I am a 53 year old British lady who generally eats a well balanced diet of food prepared by myself from mainly raw ingredients, avoiding a lot of processed or pre-prepared foodstuffs, ie microwavable foods, etc.

    I have been diagnosed with B12 deficiency via a blood test which showed 205 in UK June 2010, although I tested negative for Pernicious Anaemia (PA)…

  14. Pharmacist John says

    I am 82.5 years of age, DOB 1/1/1932 Last visit to physician was 13 years ago. Last week I visited and my physician had blood test and my B12 serum was elevated (1608) All the other values were excellent. I have no visible symptoms and have been taking 5 mgm methylcobalamin daily and when I Googled it says this high B12 serum levels may show pancreatic cancer or other cancers. Would appreciate your opinions. I will d/c the methylocobalamin for now. Thanks

  15. utkarsh says

    Can nerve conduction study show nerve damage due to vitamin b12.
    I had severe vitamin b12 deficiency 76pgml.
    It was untreated and undetected for over an year.
    I have all the symptoms of nerve damage .
    My shoulder and back pain is constabt since 1 year.
    Can anyone please help which test can confirm nerve damage and on which body part should it be done.
    For eg: i have pain in my shoulder and back.so should it be done there.?.
    Please notify me at [email protected]

  16. utkarsh says

    Can nerve conduction study show nerve damage due to vitamin b12.
    I had severe vitamin b12 deficiency 76pgml.
    It was untreated and undetected for over an year.
    I have all the symptoms of nerve damage .
    My shoulder and back pain is constabt since 1 year.
    Can anyone please help which test can confirm nerve damage and on which body part should it be done.
    For eg: i have pain in my shoulder and back.so should it be done there.?

    • Deborah says

      I was measured at 40pgml after being ill for about 2 years, i had all of the symptoms of nerve damage in my hands and feet and was in receipt of hydroxycobalmin injections for about 5 years which only brought my levels up to 330pgml. I was still severely symptomatic, nerve problems, pains, numbness and tingling and brain fog and fatigue.
      I started doing a B12 sublingual along with a Bcompelx that contains methlyfolate(metafolin) rather than folic acid among other things (fish oils, adB12, gamma E complex).
      within 3 months my levels were at 850 and almost all the symptoms were gone including the depression that had plagued me for years. i’m going to be taking these supplements for life but if i don’t feel the way i did before then its worth it!
      hope this helps and you get better

  17. Goethy Revollo says

    I’m confused. What does it mean when you have high levels of Vitamin B12 with supplementation? Tested at 1665 pg/ml. That’s with 5,000 sublingual methyl supplementation. I read Chris’ comment about a high level ‘without’ supplementation so i wonder if a high level WITH supplementation is expected. How can we know for sure if the body is absorbing B12?

  18. Jacquie says

    Hi I’m going for an active B12 test next week as my GP has moved my jabs to 2 monthly in past year and when I was having them weekly by week 5 I was just starting to feel some change and by week 15 I was feeling quiet a bit better not perfect or as I used to be but at least 75% better. Then my bloods came in at just over 900 and GP basically thinks I’m cured so moved them to 2 monthly and I got to nearly the second week and all my symptoms was back but seemed worse than before (they probably wasn’t but as I had not had most of them for sometime I think they just seemed worse) and I spent several nights sobbing and wishing I had never ever had the jabs as I would not have felt what it was like to be somewhat normal. It’s taken me a year to get a different GP to agree to refer me for active test (of which I have had to pay for but a small price if it shows that a lot of my b12 is not active then I have something to argue with). I just want my life back as much as possible.

  19. karen alessi says

    Hello Again, I am referring to Nature’s Way potassium chelated which you have recommended. Thank you.

  20. kare alessi says

    Hi Chris, Can you recommend another potassuim chelated as I am grain free and this contains millet. thank you.

  21. Carol says

    Oh and my blood work also said I had low iron saturation (13 and should be 20-50) and my iron was very near the bottom of the range (42 in a range of 37-145) and my urine showed a small amount of leukocyte, elevated RBC, elevated WBC and elevated epithelial cells, although the doctor said none of this was enough to worry about…is it?


  22. Carol says

    I’m 57 and recently started feeling sickly; brain fog, no energy, no interest, no concentration, very winded after climbing stairs, problems sleeping, bowel urgency. Went to an RA and he tested me for autoimmune because I always get a + ANA (1:160) and my B12 was almost 1,200. I asked him why and he said not to worry about it (I don’t supplement). So he sent me on my merry way. I know through 23andme I’m also heterozygous for the C677T (as well as several other MTHFR genes that I know nothing about, but not the A1298C). I’m also heterozygous for several of the MTR genes (which I understand have something to do with B12). I also had 3 miscarriages due to high antiphospholipid antibodies (but I now test negative) and was diagnosed with a vascular disease (eyrthromelalgia) about 5 years ago. I was scheduled for surgery last week due to calcification on my shoulder that caused a full tear and separation in my supraspinatus rotary cuff tendon and I can’t raise my arm over my head anymore, but I postponed it because I do not want to go into any kind of surgery not feeling strong and healthy (plus I’d have to wear a sling for 6 weeks…yuck!). I’m going to see an integrative doctor next week and hope he can give me some answers. Just wondering…does anyone think that MTHFR could have anything to do with the calcification? Thanks!

    Also…loved and am sharing the video about low b12!

    • Jacqueline says

      Hi carol…I have all same symptoms as yourself and more. I also could not raise my left arm above my head….it was very very painful, very very stiff and also hard to shave under my armpit. The specialist I saw just wanted to inject it with steroids which I refused as I know family and friends that have had similar (but in different joints) and steroid injections have not worked, or have taken a month to work then only last a month. I just every day slowly raised my arm as far as I could then bounced it gently (until I got a bit if pain and uncomfortableness) and now I can fold my arm behind my head and almost raise it to where I could in the past. Also I have in last 6months or so got severe pain in my left foot, just had X-ray to check no breaks but doc thinks plantar facilitus. Everything with me seems to be more isolated down my left side. Also at mo I have quiet a bad pain in my left lower back area (feels like a urine or bladder infection but I know it’s not…so don’t know wat that one is).

    • Ann says

      I had the same problem. I could only lift my left arm to the level of my shoulder. I had been to the GP, did the MRI, he suggested surgery and I passed, so sent me to PT, which did nothing. When reading about histamine intolerance, I came across Frozen Shoulder which is caused by a reaction to citrus. I eliminated ALL citrus from my diet and my armed went back to normal within 3 weeks (after not working for 4 years). That was a year ago and I can still use my arm. I doubt surgery would have given me the same results. I’d love to know if you consume a lot of citrus.

      • Carol says

        Hi Ann,

        I don’t eat a lot of citrus. That’s great that you figured out what was causing yours. I’m going to look into that a bit more and see if it is something I’m eating. I had no idea the calcification was forming until it was so large that it would catch on the bone when I tried to raise my arm and by that time it has already caused a full tear of the tendon.

  23. Anil Purohit says

    Hi Everybody,
    I am from India, male 35 , 110 Kg Weight , 5′ 11” got recently tested vitamin B12 with 160 pg/ml (Picograms per milileter) ?
    How much medication of Methycobalamine Injection or HydroxyIcobalamine Injection I should take per day till how many days for replenishment?? What happen if i took excess medication??
    You can advice me any other options if necessary…
    Looking forward for your reply.

  24. Derek says

    Are the co-factors necessary in the supplementation of B12? Or can just the methyl B12 be taken for good effect?

  25. Sasha says

    I have a rare genetic condition (Ehlers Danlos Syndrome) where I get severe joint pain – to the point where I can’t get out of bed some days. However since starting a mostly plant based diet (I eat meat maybe once or twice a week (hormone, antibiotic free from a local farmer)) and going vegan in other aspects and doing the whole organic local thing I seem to be getting somewhat better.
    I am concerned because my family has a history of B12 deficiencies. I take pills and I am looking at getting shots done soon (I take so many pills for my illness that I often forget to add in my vitamins.) after approval from my specialist.
    My question is what else can I do to help the B12 be absorbed – since this is a family problem. I can not eat anymore meat without potentially compromising my health.

  26. Daniela says

    Hi, I am a lacto-ovo-vegetarian for 7 years, did my blood test, everything is fine except b12(holotranscobalamin is 20 pmol/l, where normal value stated is >=50). I started taking a total of 1000mcg/ day orally a month ago. Please tell me if this should work and how soon should I test the active b12 in my blood again. Please help me, my doctor barely knows anything about the subject.

    • Daniela says

      After 2 month of taking oral cianocobalamin (1mg/day),I tested again, my levels were 128 (above 50). Now I just take 1mg/week so that it doesn’t go down again.I hope my experience with this helps others too.

      • Daniela says

        My doctor didn’t know much about b12 in general, but after research on internet, I found a local lab that had the test on their list (I’m from Romania). It cost me around 20 euros and it came back in about 10 days because they sent it to a lab in Berlin, as it stated on the result sheet.

  27. kristyne says

    29 years ago my husband had 18 inches of colon removed and was told he would need B12 because his body would no longer manufacture it. Several years later a new doctor said he did NOT need the shots and no other doc has suggested them since. So Chris, do you have a perspective on that? I am primarily vegetarian, he is a meat eater.

  28. Caroline says

    Does there always have to be a systemic cause for B-12 deficiency for non-vegetarians? I was just tested and have a very low 189 for B-12. I have had some “buzzing” and “tingling” like sensations but my energy, focus, etc. is fine. I was shocked it was this low. My doctor says it could be celiac or PA and ordered a bunch of tests. Does anyone else have unexplained B-12 deficiency after ruling out more sinister causes?

    • utkarsh says

      I had my level at 76pgml.
      I was shocked too and so were the doctors.
      I have always been a non vegetarian.
      I’m taking 1500 mcg methylcobalmin injections/day now.
      your levels aren’t very low though,still you should consult a good doctor.
      He’ll help your better.
      Peace and good health.

    • Penelope says

      Hi Caroline, I have unresolved B12 deficiency which is neither PA or Celiac. It is frustrating not knowing the cause.

      I made my first post 18 & also 30 July so really new at this.

      How are you getting on now?
      Good luck,

  29. says

    Hi, a good friend of mine has been having injections for some time now because He has b12 deficiency, He gets terrible, no energy and to be honest he looked terrible.

    I buy vitamins such as multi vitamins in spray form, I told him to this a try http://sprayavit.net/product/vitamin-b12/ as I find there products very good, since He has been using the spray He seems much better and doesn’t have so many injections.

    Possibility worth checking them out?

  30. Shelli says

    Does anyone have thoughts on the MegaFood brand of B12? I have been taking it because it’s a whole foods derived vitamin and I also like what I read about the company (non GMO, etc). My concern is that Chris mentioned that yeast derived B12 is not effective, and as I understand it this company feeds B12 to s.cerivisiae. Thanks.

  31. Tom G says

    Most interesting info, ‘wrong.’ I look forward to learning more about B-12 in the human diet.

    I want to report preliminary results of my personal ‘test’ of the precise B-12 supplementation regimen Chris recommends. I ordered and received the four (4) supplements: B-12; Potassium; Folate; Trimethylglycine (TMG). I take one each daily after breakfast. It has only been a few days since I started, but I have a few observations: 1) I seem to have more energy; 2) I’m more alert and my concentration has improved noticeably, a big plus if in fact this is due to the added B-12 supplementation; my digestion perhaps has improved slightly; 3) improvement in mood stability, again not sure if this isn’t due to something other than the added B-12, in fact not sure of any of this very early results. It will be interesting to track longer term changes in mental and physical health. I’ve added the same measures to my daily chart.

    One result, having to do with tolerability taking the supplements. The first day I took the B-12 first and almost immediately felt queasy. This unpleasant feeling lasted a few minutes. I hesitated taking the remaining 3 supplements, and didn’t take them until a few minutes later, after which the queasy feeling in my stomach abated. The next day and since I take the other 3 supplements first, Potassium, Folate, and TMG, and wait 5 minutes before putting the B-12 lozenge under my tongue, where it remains until fully dissolved, a process which takes several minutes to complete.

    Finally, I have noticed only a slight change in the color of my urine, a faint yellow, after taking the supplements. I don’t know if this is due to the slower and presumably improved absorption of B-12 into my system, but I thought it worth noting since my prior experience with B-vitamins I have had a marked yellowing of urine.

  32. wrong says

    You are wrong, chris :


    “UK official recommendations have decreased in recent years, the body’s needs having been previously over-estimated. Indeed, the Department of Health recognises that some people have lower than average requirements of B12. A whole lifetime’s requirement of B12 add up to a 40 milligram speck of red crystals, about one-seventh the size of an average tablet of aspirin!

    Vitamin B12 is excreted in the bile and is effectively reabsorbed. This is known as enterohepatic circulation. The amount of B12 excreted in the bile can vary from 1 to 10ug (micrograms) a day. People on diets low in B12, including vegans and some vegetarians, may be obtaining more B12 from reabsorption than from dietary sources. Reabsorption is the reason it can take over 20 years for a deficiency disease to develop. In comparison, if B12 deficiency is due to a failure in absorption, it can take only three years for a deficiency disease to occur. Since vitamin B12 is recycled in a healthy body, in principle, internal B12 synthesis could fulfil our needs without any B12 being provided in the diet, but there are other factors to be taken into consideration such as whether there is sufficient cobalt, calcium and protein in our diet to ensure a stable vitamin B2 level and the condition of our intestines.”

  33. Tom Gossard says

    OK, I’ve ordered the full complement you recommend via your links. Up until now I’ve been taking Solgar B-complex “50” solo to supplement my 1Xday multivitamin. I’ll see what difference(s) there might be in the way I feel taking the poly-supplementation versus the mono-supplement B-12 complex.

    I’m retired and living on a restricted fixed income, hence I need to make careful choices with as low a price for the best quality supplements I can afford. Your 4-supplements cost me more than twice what my present 1 supplement costs. So I will be alert for positive and negative effects on how I feel overall.

    I take a Consumer Reports highly recommended Multivitamin Senior Formula 1 X day. My only other supplements are a C complex, D-3. Finally an Omega-3 fish oil supplement made by Nordic Naturals, or OmegaBrite, as adjunct to the prescription medicines I must take for severe Bi-Polar Depression. The Omega-3, by the way, has been a real life-saver for me, as its positive effects on mood are palpable and reliable. They get me through the more depressed periods I periodically encounter in my mood cycles.

    Thanks again for your marvelous website. It’s a g-d-send to know where to go first for good health advice and recommendations.

  34. Michele says

    Hi Chris,
    I was diagnosed with Pernicious anemia, shortly after they found carotids in my stomach. I’m taking b12 supplements but as you know, my body can’t absorb B-12 so it still futile. I have nerve damage already, but they’re attributing it to the bulging disc in my neck that are cutting into my spinal cord. My Neurologist and thoracic Surgeon can’t 100% tell my why my arm goes numb, ice cold and is in pain 24/7. I’m 44 and at the end of my rope.

  35. Amy says

    Chris, can you recommend any supplements (especially b12m,, magnesium and vitamin A) that do not use any magnesium stearate? I have lupus, leaky gut, etc., and when I take any thing with magnesium stearate, I my face literally bleeds! I get horrible blisters that turn into open wounds. That sounds graphic, but from trial and error I have found that this is absolutely connected to magnesium stearate. I can’t have anything containing rice syrup or gluten, either. Any suggestions would be so appreciated!

  36. Kathy says

    Do you have B12 suppliment recommendations for people with diabetes who have been on Metformin for years? Most of my doctors are not familiar with B12 deficiency as a side-effect of metformin.

    I development numbness in both toes after taking Metformin for 5-6 years. I went through a bout of accupuncture and realized that the numbness had gone away. But it comes and goes. Dr. Oz had an episode about Vit B12 deficiency.

    Since then I have been taking sublingual B12 starting at 5,000mcg. My doc suggests taking 1000mcg per day. My question is that while I no longer have the neuropathy in my toes, I still have other symptoms, can’t recall people’s names or words and have general fatigue and problems sleeping. \

    What is a reasonable amount to take both orally or in a shot. It’s been difficult finding doctors to give shots.

  37. Lesley says

    Hi Chris,

    I love your site, so informative!

    Do you know of a brand of B-Complex that contains folate and NOT folic acid? I’ve been trying to find one to no avail. I cannot ingest folic acid due to MTHFR mutation. I do supplement with 5-methyltetrahydrofolic acid but want to also take a B-complex. I do eat a Paleo diet.


  38. says

    One of the most commonly prescribed drugs is Nexium (for acid reflux). I was on this drug for years, only recently stopped taking it. One day I went to the doctor, she ordered a blood test, and the result showed a vitamin B12 deficiency. I did more research and apparently Nexium decreases absorption of B12, meaning most people taking Nexium will find themselves B12 deficient.

    The Nexium pharmaceutical drug is quite insideous. You can’t stop taking it or you will get really, really bad heart burn. The drug is probably designed to achieve that result. Thankfully I have been able to significantly lessen the need for it by upping my intake of raw unpasturized saurkraut and also cutting out wheat and processed foods from my diet.

  39. Sarah Lewis says

    Hi Chris,
    I love that you’re writing about B12. I have a personal interest in it, and specifically methylcobalamin. As an RD, I see tons of patients with nutritionally related problems and thanks to having access to great, advanced labs and genetic screening, I get to also help them with methylation pathway concerns.

    I know that I carry the two heterozygous mutations of MTHFR genes (677 and 1298) so my methylation is reduced quite a lot. I take 15mg Deplin (l-methylfolate) daily, and have in the past supplemented with methylcobalamin, although, admittedly not as frequently and regularly as I should.

    My question is what are your findings, if any, with people who carry a methylation defect like that? I’ve never had low B12 on a standard serum test, but I don’t think the serum tests are very accurate for someone in my circumstances. I eat red meat almost daily, as well as eggs daily, so I don’t doubt that I consume enough B12, but I know that I’m also very sensitive to some food proteins (soy, gluten and casein), and I know that if I don’t take a high dose probiotic every day, my skin breaks out. All these lead me to the conclusion of gut dysbiosis of some degree.

    So I guess my question is really, despite the fact that I eat a lot of B12 containing foods, am I possibly not absorbing a lot of it, and, I don’t know if you know the answer to this, but were I to regularly take my methylcobalamin supplement, would there be a noticeable difference in energy levels, etc after a certain amount of time? Just some random thoughts :) keep up the great content!!

    • Lesley says

      Hi Sarah,

      I carry one copy of 677T and have high serum levels of B12. I do take a sublingual form of methylcobalamin 5,000 mcg. 4-5 times a week. I also question how accurate the serum test results are as I also had to have 10 inches of my mid-jejunem removed due to perforation so I know my absorption is somewhat compromised. Have you worked with clients who have had some of their small intestine removed?

      Have you checked out http://www.mthfr.net? Great info and suggestions on how to mitigate the effects of carrying the gene mutation.

  40. April says

    I am celiac/hashimoto’s and vitamin d deficient as well as low b12. I was taking 1 teaspoon of FCLO which did not make a dent in my vitamin D level so I’ve upped it to 2 teaspoons daily. My question…How often can I safely eat (4 ozs.) of liver for to increase my B12 without having to worry about too much Vitamin A from the FCLO? Can the combined eating of liver with supplementing the FCLO make me Vitamin A toxic? I really prefer to eat the food over supplementing. Thanks for all you do.

  41. Pam says

    Hi Chris,

    I have been dealing with chronic illness for 2 1/2 years. My B12 levels from day 1 have been high, especially now that I have been supplementing with standard process and taking what my body needs through applied kinesiology. I do still have neurological problems, tingling etc. We recently did an intrinsic factor test to see if that is why my blood levels were so high but it was normal. Is this test enough to prove I don’t have a b12 deficiency even though my level are in the 1600’s? I have been trying to get some information over the web, but not a whole lot of explanation for those that have high levels. Thanks for you time..

  42. says

    I’m not sure what’s scarier, the sheer volume of hateful, malicious, self-serving comments or the overall fact distortion echoing throughout this entire page (from both sides of the discussion) but anyone blind enough to think any single lifestyle or diet is perfect is fooling themselves.

    We’re all humans who are lucky (and unlucky) enough to exist in the world at this one blip in time with more knowledge, more choices and more freedom to shape the world, our health and the health of the entire world (Humans, Animals, Earth, Water, Sky) in its every shape and form for the better!

    There are billions of evolving data points that cover every manner of study, every branch of science, biology, ecology, chemistry, archeology, history, past & present with infinite contradictions, numerous correlations and plenty of both. All of that and none of that make it easier to know what to do but at the end of the day there is YOU and there is EVERYTHING else. All the other people, animals, plants, earth, land, water, sky, pollution, health, sickness, happiness and suffering of everything that is and everything that will be and well to me, that means my food, my diet, my health, my choices are about more than just ME.

    Of course I want the healthiest, happiest, most nutritionally balanced radiant life possible but when I add it all up, including the infinitely debatable elements of “food” that will inevitably evoke disagreement for all eternity, it’s clear that the individual and collective human effect of living and eating vegan is more positive than negative, more health than sickness, more light than dark.

    So I say #GoVegan (….‘cause the entire world is likely worth a few sublingual B12 :)

  43. Gerry Thompson says

    Hello to everyone. Chris, thank you for bringing up the B-12 issue. My husband, Don and I have wondered about nuturtional deficits in my diet. I have had gastroparesis now since 2006 when my vegas nerve was damaged during a hiatal hernia repair. I do pretty good now at keeping food down and have been able to achieve a bit of reserve weight. The comparison for this is 3 years ago I was down to 108# as I was not able to keep food into my system. At one point I was sent to a specialist for memory loss as I have periods of aphasia. This is dietary related aphasia. You don’t eat for 3 weeks, stuff happens. I think I will try adding the b-12 supplement to my herbal supplement and vitamins. It would be great if it could help to defeat some of the aphasia.
    Thanks again, and I will see if your diet ends up being one that a dead stomach can deal with.

    • Ann says

      I credit my aphasia to lamictal. Never had it before and my memory and speech improved dramatically when coming off of it. Are you on any meds?

        • Ann says

          Hi Kathy,

          I’ve talked to many neuros at events (not my MDs) and they all claim there is no problem. While they see many people on the meds, they don’t live with them or take the meds. I’ve been on different meds over 40 years and lamictal made me clueless, affected my speech greatly, which never came back 100% and slowed me down. I would never recommend it (although I didn’t mind the weight-loss side effects). Do ask MDs questions, but go with your gut about what you think is happening as well.

    • Sarah says

      Low-carb/high-fat Palaeo. Read Chris’s articles. You don’t need carbs – and you CERTAINLY DON’T need grains!

    • Sarah says

      B12 DOES NOT give you energy; it assists in enabling you to convert food to energy, but it doesn’t give you energy in – and of – itself, like caffeine does.

    • RieRie123 says

      I have brain fog. Literally, your brain is in a fog. It’s like being half asleep. Everything is fuzzy. Mine is from a head injury.

  44. Janet B. says

    I have been diagnosed with B12 deficiency. I went to a hemotologist who put me on weekly injections. This helped bring me out of the fog. I was a walking mess! After two months, she pronounced me cured and told me I would need to learn to do shots twice a month. I tried to live like that but it is just not enough. I have gone back, she then increased it to 3 shots a month. However some of the symptoms are not going away or becoming less. It is worth noting that I take a protein pump inhibitor, metFormin and I do eat meat. I have significant neuropathy in my feet which is progressing up my legs. I feel like I need to see a doctor that specializes in this issue, but do not know where to start!

    • Lesley says

      Alpha lipoic acid helps with diabetic nueropathy. In the form of R-lipoic acid it is most active. You didn’t mention what type of diet you follow but adopting a Paleo diet, eliminating all grains is likely to reverse your diabetes.

      Interestingly, the reasons doctors prescribe proton pump inhibitors; acid reflux, heartburn, hiatal hernia are actually due to not enough stomach acid…not too much! You need acid to absorb vitamins and minerals, kill pathogens including h-pylori the cause of ulcers, break down and assimilate your food, especially protein.

      My mom took Prilosec for years unnecessarily. I helped her get off the drug by initially taking 1 Tbs. of lemon juice with her meals. She then transitioned to taking hydrochloric acid with pepsin. She did have rebound heartburn for a couple weeks, the lemon juice helped with that, but got off the drug permanently with no ill effects. She still takes the HCI and pepsin and is doing great at age 86.

      BTW – our stomach acid production declines as we age which helps explain why so many doctors prescribe acid blockers to older adults.

  45. Walker says

    For what it is worth, I was a vegetarian (no flesh at all) for almost 20 years. At my last Dr.’s appointment, my physician said my B12 was way too low (interesting no other Doc mentioned it before). In addition to a supplement, she ‘ordered’ (in a good sense, of course) me to resume eating meat at least 3 times a week. I can remember trying to ‘negotiate’ that with her, and she would have none of it. I have since gone Paleo and feel so much better. Good for her, and stupid of me for not understanding the science better.

  46. Kelly says

    Hi Chris,

    I am a long time vegetarian who exhibits a lot of the symptoms of b-12 deficiencies. My b-12 level was considered normal (331 PG/ML), but I pressed for MMA and Homocysteine testing. Can you tell me what the normal range is for MMA and Homocysteine? My doctor tells me my levels are normal, however, I’m not sure what the normal levels are. My MMA result was 286 nmol/L and Homocysteine was 9.9 uMOL/L.

  47. Terri says


    I was just diagnosed with a functional B12 deficiency. My B12 is 68. I am so tired and weak. I start weekly B12 injections next week.
    My question is what does a functional B12 deficiency mean?

    Thanks in advance,


  48. Ann says

    What does a low MMA mean? I started taking B12 and it has increased, but I’m still dropping in the iron and my MMA was below normal.

  49. Joan Turner says

    My dad has B12 deficiency and was switched to Sub lingual B12 instead of the shots. He seems to be more fatigued. Has anyone found the shots superior over sublingual?

    • says

      For me the sublinguals or the B12 drops never worked. I went back to methylcobalamine shots every 2 weeks for 2.5 month. The tingling stopped within 24 hours of receiving the first one.
      Now I am experimenting with B12 patches (ordered from Kevin Gianni) and they seem to work.
      I am much more watchful of my B12 and D3 levels nowadays and after reading some of the many comments here have to distrust some of the blood test results.
      I would definitely consider the shots for your dad.
      Good luck!

  50. JRS says

    Hello Everyone, Great Info
    I have SIBO (after long term PPI use) and my B12 levels dropped by 1/2 3 years ago. My last test showed low B12 @ 362, Folate at 614, and Cortisol – high – possible adrenal stress?
    I have problem with taking B12 (tried methylclobalamin drops)….but became very agitated and couldn’t tolerate the smallest amount. Sublingual pills made me very racy.
    What would be the best choice. I just realized about the Cortisol being high – my doctor didn’t say anything about it – but just realized that she noted – possible adrenal stress? That makes me nervous – is there a test I should order?
    any suggestions are so much appreciated.
    Thanks for all the wonderful information that we just cant get from our medical community.

  51. Nandadeep says

    Hi Chris,
    i was tested my B12 in may 2012, it was 617 and last week in 05Dec 13 my B12 was 161. Now i took 2B12 – pill -1 per day. Before that i explain previous history, in Dec 2012 tingling in the legs and arms was started , i went to Neurosurgeon he told common , then in March 2013 i did MRI brain its normal, Then for tingling my Neuro told me to go for EMG and he found evidence of neurological disorder without any symptoms , for 2 nd opinion i went another Neuro surgeon he just rule out and supplemented E vitamin and antioxidant for 3 months. One day i just went and did all my blood tests and found it vitamin D deficiency. it was really poor clinical examples that our physician first do basic things like blood check . I did MRI brain, spine . EMG – 2 times and finally got B12 deficiency.
    i would like to ask
    1. Why within 18 months B12 drop by 500
    2. Within1 year is there any chances to permanent damage of Nerve system?

    With regards,


  52. Elliecee says

    How likely is b12 deficiency in a long-term SIBO patient? I’ve had SIBO for 4-5 years. Over the past 2 years I’ve had intractable depression and anxiety and 2 normal serum b12 tests. Trying to decide whether it’s purely mental, or if I need to insist on further b12 testing.

  53. Mark says

    Greetings Chris & all other contributors!

    My sister & I were found to be low B12 (133) and low D (9-10) & are now on Methylcobalamin Injections + supplements! My father was also low D but was borderline B12 at 240 so got his Homocysteine done & it was elevated at 21 umol/L- so he’s on B12 shots & occasional Solgar Folate (as his Folate levels have always been good).

    Now the problem is my Mother! Seems it could be hereditary (ie in our genes) to be Deficient! Her B12 has been very normal at 500 but D was low at 20ng/ml however she has low energy, irritability & most importantly a very severe and nagging Nerve twitching in her tooth gums that no neuro-surgeon has been able to control. So I suspect she could be low in active B12.

    Hence need to decide whether to get a Homocysteine Test OR serum MMA Test OR Holo-Tc Test OR an active B12 serum Test? Am confused and all these Tests are extremely expensive in Hong Kong so would like to resort to 1 Test for now.

    Thank you in advance for all your help and guidance!

  54. Vivien says

    Hi Chris, Have you come across the claim that “oral methylated forms (of B12) chelate heavy metals that may be used as dental fillings” ? The (reputable) company making this claim only uses cyanocobalamin lozenges and warns against the use of methylcobalamin lozenges. I’ve written to them to supply relevant research data, but have had no reply.

  55. Jonah says

    I was an undiagnosed case of b12 deficiency. My symptoms were; peripheal neurapathy, chronic fatigue, muscle aches and stiffness, insomnia, night sweats, anxiety, extreme self anger ( I would verbally curse my self with profanity everyday) constipation, mild brain fog(I could not read a book without dozing off but never felt rested). It was a three year nightmare. I did not have insurance to see a neurologists but thankfully self diagnosed thru internet research and began taking methyl cobalomin. It was a true miracle and I am
    not exaggerating. Within days my symptoms began to dissappear. It is now 4 months later. I sleep like a baby without night sweats or anxiety. I can read without dozing off. I feel rested. I rarely curse myself. I can work 12 hour days. I have no muscle aches or stiffness. I began exercising. I am so happy. The only thing that remains is a light numbness in my feet and uncomfortable pressure in legs when i cross them but i rarely notice because i feel so good. My doctor did not suspect b12 deficiency because my levels were normal. I was prescribed oxycodone which i no longer take. I thank God everyday and his doctors and scientists.

  56. Eduardo says

    Hi, thanks for pointing out an important issue for vegetarians and the general public. Two things I would like to comment: (1) animals DO NOT make B12, bacteria in their gut do. From wikipedia: “Neither fungi, plants, nor animals are capable of producing vitamin B12. Only bacteria and archaea have the enzymes required for its synthesis, although many foods are a natural source of B12 because of bacterial symbiosis.” (2) Milk is an excellent source of B12. Would you agree that lacto-vegetarians have enough dietary intake of B12?

  57. Erin says

    Thank you so much for your kind responses! I’m so frustrated and am agonizing over this. I am certain I have a deficiency but the drs just won’t listen. I went back in and persuaded them to run b12 and they just called and said I’m totally fine and recommended I take a daily multivitamin! My b12 read at 483. Should I look for an actual hematologist? I dont have insurance so each visit, each lab test, is all out of pocket. I need to figure out who to see that will help me fix this problem because I cant keep going back over and over. I’m in Florida, is there a website or something to help find a Dr that understands b12 deficiency? And thank you so much for that video, it was a huge help! If only some drs would watch it as well.

    • Ann says


      I would google B12 deficiency, testing and Florida. I don’t know if the MDs will find 483 low, but when you find someone to check it, ask them to do the MMA test. Are there other things that make you think you have a low B12? I found out mine was low when checking for histamine intolerance and mast cell activation disorder. You seem to have a lot of those symptoms. I would read up on them.

    • Maria says

      Really good book on B12.
      Could It Be B12?: An Epidemic of Misdiagnoses by Sally M. Pacholok and Jeffrey J. Stuart

      Blood tests maybe misleading if you have MTHFR gene mutation or your body has difficulty metabolizing B12. Levels may be high because cells are unable to access it.

  58. erin says

    I have pretty much all of the symptoms (tingling/soreness, constant exhaustion regardless of sleep, confusion, weird tongue, memory loss…) was pretty certain b12 deficiency was the culprit (I’ve been a vegetarian for 19 yrs). Went to the walk-in since I don’t have a primary and they called to tell me blood tests were totally normal (they did a cbc and 2 others that were thyroid related). I’m feeling pretty clueless now and not sure what my next step should be? Are there specific tests I should be asking for; is it even possible that a cbc would not detect b12 deficiency? My half sister has Ms and had her thyroid radiated years ago for graves disease. Would so greatly appreciate a point in the right direction!

    • Ann says

      I would ask what the results of the B12 test was, rather than if it’s okay. Supposedly 200 would be okay, but some docs don’t feel this is accurate and can contribute to neuro problems. Find out where you are in the B12 zone. Also, start reading about histamine intolerance, mast cell activation disorder and HNMT and DAO enzyme deficiencies.

      • Erin says

        Thank you! I looked into histamyne and enzyme intolerances but that doesn’t appear to be related to me as much as b12 possibly does. I picked up my lab results, do you have any idea what the ranges can say? Hemoglobin was 12.7, hematocrit 39.4, & mcv 93.6? Do you know if that indicates a b12 deficiency? And thanks so much for your reply!

        • Maria says


          A regular serum B12 level is not enough to diagnose a B12 deficiency. You may have high levels in your blood and it may not be getting into your cells. Please watch this video, it explains the best way to diagnose and test for a B12 deficiency:

        • Ann says

          Erin. Here are the normal ranges.

          4.00-6.00 10^6/uL RBC
          11.0-18.0 g/dL Hemoglobin
          35.0-60.0 % Hemocrit
          80.0-99.9 fL MCV
          27.0-31.0 pg MCH
          33.0-37.0 g/dL MCHC
          11.6-13.7 % RDW

          I don’t know if a low B12 would be reflected in those #s. I do know mine are low and my B12 was down to 233, which reads okay according to the US range, but my MD (from Scotland) said it’s not okay and since I had neuro problems (epilepsy) he put me on B12. My last reading was up to 483 and I”m going back tomorrow for another test. The most interesting thing I find is that my B9 (folate) is decreasing as my B12 increases. You would need to be tested for B12 to get your B12 level. Watch the video suggested in the other reply to see the specific tests that can be done.


          • Kathy says

            Hi Ann,

            Diagnosed with severe B12 deficiency and received my second weekly injection today. I have epilepsy, too, and wonder if there might be some connection?


            • Ann says

              I’m surprised at how many people who post on sites with B12 deficiency or histamine intolerance do mention epilepsy or seizures. Don’t know if they’ve ever done studies on it.

  59. Nahal says

    Hi Chris,
    I am a vegan and I been having symptoms of low b12 like tingling or numbness in fingers and toes, weakness, tiredness,mood changes, depression, memory loss, trouble concentrating. My b6 came back normal. My b12 is 354 which my doctor said was a low normal and my d3 is 15. Can my symptoms be from my vitamin b12 or because of my vitamin d deficiency?

    • Aliz says

      Gosh, you have severe vitamin D deficiency! Yes, the tingling and numbness can definitely be the result of that. This is how it started with my friend, too, who now has MS and lives on a daily 5000UI vit. D. Regardless of what you do with your B12, I’d recommend to start taking vitamin D supplements immediately!

      I’m vegan, too, with similar B12 and 69 vitamin D, and I’m taking both supplements.

  60. Hen says

    Megadose sublingual B12 treated my Herpes zoster ophthalmicus!!!

    Just 4 days and my blisters dried and soon to fall off! Anyone knows what it’s like to have that disease will swear how excruciatingly painful it is. Aside from depression, affected brain, and affected eyesight–possibility of blindness.

    My specialist doctor just prescribed paracetamol tramadol..and saying it will heal as time goes on! WTF! I felt a lot of pain and “PRESSURE” in the back of my left eye, and afraid of losing my left eye, and be blind. I analytically I thought that paracetamol is just for pain, but IT WILL NOT treat my progressing zoster ophthalmicus. So I searched and found an article, that in Indian research, b12 is the treatment!

    This doctor also said she don’t believe in supplements, when I said I was taking megadose vitamin c.

    Discern who to trust. Use your common sense. Because some doctors are incompetent.

    • pam says

      Hi, Han,

      interesting, i have never heard of it.

      what is the dosage you uses? but last time i had my blood tested, my B12 was pretty high
      so you think i should still try supplement B12.

      (it was very painful + my L eye didn’t see very well for 2 weeks)


  61. gowrie says

    Please do not make categorical analysis about vegetarians without having a clue about vegetarianism. Western vegetarians cannot form a sample for Indian vegetarians by any stretch of the imagination. In the west, there is a colossal shortage of edible and cuisine fit vegetables. What you have is peanuts compared to what is available in a largely vegetarian society like India. The imagination rich cuisine of India ensures that all those symptoms you speak of do not occur in the well nourished vegetarian Indian. Having 80 year olds with excellent memory and no strokes (and these are folk who don’t touch eggs, seafood, and any form of meat) was a common factor in India.

    So before you spout out meaningless analysis in the name of having done research, be careful about the language you use. Specifically, confirm that when you refer to vegetarians, you refer to White vegetarians living on Western vegetarian diet. I have tasted the vegan diet. It tastes abysmal. Only self denying gluttons for punishment would go for such a diet. The subcontinental vegetarian diet, which is promoted in India and forms the basis for a yogic lifestyle is largely misunderstood by the linear thinking western rationalist, who lives his life like a horse with blinkers on, believing he has understood all there is to be understood.

    • Aliz Meszaros says

      So, what’s the difference exactly in your opinion? The variety of available vegetables?

      I live in London and became vegan when I read a linear thinker’s book called “The China Study”. Yeah, science stuff and sort. There are ethnic markets around here, btw, with all sorts of vegetables, even things that I have never seen before. Obviously, I’m just a narrow-minded Westerner who knows nothing, but the variety seems pretty great here if someone’s interested to have it…

      • Sarah says

        THE CHINA STUDY…?! You mean to say there are STILL people gullible enough to fall for Col’s Collossal Con…?! Well, ya know what they say about suckers…

        So, basically, you became vegan for “health reasons”, and based those ‘health reasons’ on a book written by a quack who faked most of his ‘research’. Colin Campbell DID NOT write that book from a truly objective perspective, he wrote it as someone pushing an agenda – NONE of his ‘research’ stands up to even the SLIGHTEST casual scrutiny – I’ve read it, and saw through the BS within 2 pages!

        http://www.rawfoodsos.com – read Denise Minger’s thorough debunking here.

        People who go vegan for health reasons are foolish – but people who read TCS as a serious piece of scientific research, quite frankly are out of their minds!

        See someone with letters after their name, and some people develop Pied Piper Syndrome.


        • Alice says

          Minger? Ah, I remember, that 23 yrs old English major who fancies herself as a statistician without any scientific background (laughed at by anybody who knows anything about statistics – obviously not you), while desperately trying to find random correlations in a 800-pages book published by a “charlatan”, only to support her own biased views on diets and gain some temporary fame for herself… (at least she succeeded with the second one – all idiots copy-pasting the link to her blog like no tomorrow). The biggest joke is how little she understands of Campbell’s warning about the necessity of a holistic view on diet… Anyway, go with her, darling, that looks like a much smarter choice. :)

          Btw, I keep an omnivore day every week (when I eat mostly fish or liver). If you read the whole book (which I doubt you did or would), you can see that Campbell doesn’t claim that eating animal food is entirely bad for you. He’s happy to admit that there’s no proof that including 5% animal protein in your diet is actually worse than including 0%. Also, while he says “avoid” meat, poultry, dairy and eggs, he only says “minimize” fish. Minimizing also makes sense if you consider some ethical reasons (I know, you are not the type with such considerations), such as the dangerous decrease of fish populations in the oceans or the massive human slavery in the sector. (In case you want to see the real cost of the fish on your plate:

  62. Ann says

    Hi Chris,

    My B12 was low, 233 pg/mL, so I started taking B12 methylfolate- 1000 mcg. A year and a half later, it’s up to 483 pg/mL, but in the same time my folate has dropped from 17.6 to 10.4 ng/mL. Is that normal? I’ve also gotten my Hgb, Hct and MVC into the normal range, but MCH 26.1 and MCHC 31.7 are still low and RDW is high 25.7%

  63. Pablo says

    you say “A common myth amongst vegetarians and vegans is that it’s possible to get B12 from plant sources like ”

    and this:



    http://www.ncbi.nlm.nih.gov/pubmed/7562085 from here

    “On the basis of these results we conclude that some seaweeds consumed in large amounts can supply adequate amounts of bioavailable vitamin B-12″

    we are talking about 5-10 gr of dried Nori.

    Plus the populations who have endogenous production of b12.
    Vegans have a higher risk of b12 deficiency, it is true, but the reasons aren’t other ones than diet alone and it is possible to not ever have a b12 deficiency without any supplementations (maybe not so easy this times).

  64. Maria Oliveira says

    Thanks for all the research you do and for your generosity in posting this important information for us; I regard you as one of the best health researchers I know and trust your opinions. My 17 yr old daughter who is Compound hetero MTHFR scored low for B12 on the Spectracell test, so I’m going to start her on your recommended supplements. However, I question whether to start her on the TMG because her homocysteine is low (5.5)?

  65. Lydia says


    I am pregnant and currently taking a prenatal vitamin with 30mcg of b12, 5 mg b6, 600mcg of folate. I am sick all of the time so a lady at the health food store recommended i take Superior Source b12/b6/folic acid combo. It’s 2 mg of b6, 400 mcg of folic acid and 1,000 mcg of b12.

    Is this amount safe to take while pregnant?

    • Amber says

      Hi Lydia,
      You might want to examine the folate source as a potential thing which is making you sick. I get sick when I take folate or folic acid supplements…no matter how small the amount. I can only handle folate in the active methylfolate form. I’ve tried many brands of multis and b-complexes, and it’s the folate/folic acid which consistently makes me ill. The only 2 brands of b-complexes I can handle are Swanson Ultra Activated B-complex, and now a new one, Doctors Best Fully Active B complex (both brands have the active form of methylfolate). Not saying this is your problem as well, but maybe you could look at it.
      FYI, I have one of the MTHFR mutations, which I guess is very common. I suspect this is why I’m so sensitive to the various folates.

  66. Monica says

    I am a vegetarian…and have been almost all my life. I just turned 40 this year and have had some health problems…but nothing too major. 11 years ago I was diagnosed with Bell’s Palsy. I had a severe case…with all the typical symptoms that come with Bell’s. I recovered fully after about a month with the help of prednisone, rest, and daily facial massages. Well, yesterday I got Bell’s Palsy again for the second time (11 years later). This time my bout with Bell’s seems to be much, much milder than the first round. My question is…if only 40,000 people get it yearly, how come I am on my second round?? The only thing I can think of is that since I am a vegetarian (borderline Vegan) has my B-12 deficiency caused this to happen (Bell’s)? Is there a link between Bell’s and low B12?

  67. prashanth says

    As an indian and vegetarian i would like to know if the studies were carried out here? The symptons are too generic ( like every other vitamn pages in wiki). As having a long history of vegetarian( which btw includes dairy products but not eggs ) i would like to know if there are specific symtons related to indian sub-continent.

  68. Melissa says

    I am 37 years old and about 2 years ago I thought I was literally losing my mind. Forgetting everything, seeing things, etc. Bad headaches including debilitating migraines. The only thing the doctor found that was odd was low iron. I’m not a vegetarian but I don’t get a lot of red meat in my diet usually just because of the simple thing called cost. So, I was getting worse. The next appointment just low iron again and I asked to have more tests as to why. It turned out to be a little more serious but they still didn’t/don’t seem to think it’s much of a problem. The anemia was found and then the B12 deficiency. My B12 level was under 100. I now give myself an injection every other week but I only feel slightly better for a day or so after the injection then I go downhill FAST. I’m VERY worried but my doctors don’t seem to be. I don’t know what to do. Maybe I am losing my mind.

  69. Vanessa says

    Is it possible to still be B12 deficient while taking supplemental methylcobalamin B12 and having high serum B12 levels (1700) ?

  70. Joe says

    I’ve been taking Jarrow Methyl B-12 for a few weeks and would like to know if it can/should be taken with a meal. It doesn’t say one way or the other on the label.

  71. Brad says

    Hi Chris,
    I try to only use data I can verify, but I don’t have time to find studies for what I am going to ask at the end. I became vegetarian about 7 months ago and don’t plan to go back for a multitude of reasons, although I still support using animals for most forms of experimentation. I take a 1,000mcg pill a day of methylcobalamin. I heard in the meat verses non-meat debate that most animals in modern farm factories are given frequent B12 shots themselves since the animals don’t get enough from the animals’ more natural dieting methods. That kind of makes sense to me since I heard B12 is made from bacteria common in soil and chickens like eating worms and cows like chewing grass that probably has B12 in it. Do you think that the B12 meat eaters get these days from meat is more like indirectly eating the B12 supplements the animals themselves are given to avoid dying?

  72. Sandi says

    Hi Chris
    Im 50 years young and Im from Adelaide, Australia and i came your website and i am very interested in the B12. I have read the book Could it be vitamin b12. My husband had his b12 tested but i dont think the doctors here did the right one, so i was wandering if we ordered the vit b12 from the website that you recommend, would it hurt us in taking the b12 if we havent been tested. I also suffer from pancreatitis.
    regards, sandi

  73. sofia says

    So, sorry if I missed it but, what is the supplementation dosage for vegans? I have 500 ug Methycobal injections… How often them?

  74. sheila says

    Im 42 year old female started having GI problems 4 years ago GI DR diagnosed acid reflux,no ulcer,no celiac,High B12 and High Iron he said was not normal but wasn’t worried about it since it wasn’t dangerously high I advised him I do not take supplements but he still said nothing to worry about.Well here it is 4 years later and im real sick again this time with LOTS of issues …Gi issues,dizziness,brain fog,tingling limbs,blurred vision I worried myself into panic attacks and anxiey all my blood work comes back ok but again High B12 !! My dr thinks no connection no big deal I need help…now I read on your web site this may mean im deficient ???? how to I find out??Pease help ive had no life for the past 4 months!!!

  75. Ginger says

    Is it fine to boost glutathione (via undenatured whey) while doing a b12 protocol? I saw something of Fredd’s that suggested glutathione would covert methylb12 to glutathionylb12 and excrete it, though I can’t find these mentioned anywhere else. And it would seem, other sources mention glutathione as being protective of b12. Thanks!

  76. Cindy says

    Hi! I am 17 year old female. I just turned Vegan and I have started taking 1000 mcg of B12 / day. Is that alright? I also take flaxseed oil in a fruit smoothie, will that affect the absorption of the B12? I am also going to go on a multivitamin and a probiotic. (when my dad gets paid) I was considering going on chlorella too, would that be a good idea? Will any of this affect each others absorption? Thanks!

  77. marianne says

    I have SLE, anemia, high blood pressure,one bi-pass and 4 stents. I (by accident) of one of my doctor’s noticed a huge B12 deficiency and suggested 3 B12 shots a year. I did some research and found Superior Source sublingual b-12. Doing more research I felt better knowing that like Vitamin C you really cant OD on it. Subsequently I had just been taking 500 mcg b-12 in tablet form, which this particular doctor told in my case was useless. I have now been taking 10,000 mcg and some day take 20,000 and have seriously never felt better. When I bruise from my anemia or SLE they heal much quicker and overall my energy level, combine with a couple of Ensure Plus a day has truly been a life saver for me.

    Wishing everyone on this post the best.

  78. Amanda says

    Hi. I started having horrible anxiety almost 2wks ago. In the past I took a raw Bcomplex and it seemed to help so I again started taking the same BComplex. My doctor just ran a bunch of labs, including a serum B12. All my other labs were fine except the B12, which is 1700. My dr didn’t even say anything about it, just said my labs were perfect. I of course started looking it up and read about all these serious diseases that cause it. Is it possible I am oversupplementing and don’t need the Bcomplex? I know my father lacked intrinsic factor. Can high serum bcomplex be a sign of that? I’m very worried:/

  79. Inge says

    I suspected b12 deficiency a few months ago and decided to take an active b12 test plus homocysteine test. The results came back more than ok. I’ve not been eating meat except maybe 3 or 4 times a month, for 4 years. I have GI problems, leaky gut probably too, I don’t absorb food very well. You would think these two facts combined would inevitably lead to b12 deficiency… If someone knows more about this, you can always leave a comment. Thank you.

  80. Karen says

    Hibi got diagnosed with B12 deficiency October last year I had injections every other day for 2 weeks then 12 weekly now 8 weekly, before I was breathless I had chest pains couldn’t think straight got confused couldn’t retain information and forgetful was an understatement, I had numb tingly site patches all over my body my eyes foggy, muscle aches I slept for 16 hours solid and got up and still felt like I hadn’t slept and was back in bed within 2 -3 hours, I couldn’t function, I also got shingles don’t know why or how I’d had chicken pox, it was after that I was tested and my levels were at 90, now I feel great only sleeping for 8 hours, looking at how I feel now and then I must have been deficient for at least 4 to 5 years, my doctor said he hadn’t come across a B12 case where it had effected someone neurally, but still get the numb tingly sore patches but not as often, I honestly was that bad September last year I thought I was dying x

  81. Anna says

    Thank you for all the good information. Since I didn’t read every reply, I apologize if my comments are repetitious. Post gastric bypass patients are also in need of better B12 testing. I am a successful 10 year post-op who has developed issues following a hysterectomy. Hypothyroid, adrenal, hyperaldosteronism, edema, diostilic hypertension and SIBO. I just ordered some of the sublingual methyl B-12 and hope it helps. In the past I used a sublingual cyan B-12 and got high serum B-12 results. When doc does my next labwork I’ll definitely ask for urine MMA too!

  82. Holly says

    Have you ever heard of sudden onset of B12 deficiency/symptoms? For some time before these “episodes” i have fatigue, significant muscle weakness, menstrual changes, mood swings, emotional changes, etc. 5 years ago, with those symptoms having been present for some time, i suddenly – in the span of 24 hours – experienced significant joint stiffness, pins and needles in my extremities, fatigue, and when i try to sleep, i experience sudden and severe pins and needles increasing to severe burning, throbbing intolerable pain in my feet and hands. This happened repeatedly over two weeks with no answer. I was incapacitated by resulting severe heat sensitivity in hands and feet, joint pain and what felt like bruised, battered and broken feet. No swelling, no redness, anti-inflammatories have no effect. After these “foot attacks” i am crippled.
    Eventually a neurologist agreed to see me but sinve i would be coming from an isolated community and with a history of celiacs, they requested that i be given b 12 first. Note i had just startes taking seeious nerve pain killers. The b 12 seemed to help and i stopped the nerve pain killers, within days i no longer had foot attacks though i took a long time to recover from the stifnesa and bruised feeling. I stayes on b12 supplements and was suddenly more energized, improve menstrual (marked change). Etc. ive been on b12 shots, 1 every 3 weeks since. I can tell when one is due before the reminder – the muscle weakness ans fatigue increase.
    I’ve ben under a lot of stres lately, as i was before that attack 5 years ago. Nearing my three week mark for b12 i was experiencing the muacle weakness etc but wed of last week, i began to feel significant stiffness in my neck and shoulders. I chalked it up to stress and took toredol. Sat/ sun i began to have noticeable stiffness in my kneea and by sunday night-noticeable stiffnesa in hands and elbows. Within hours – noticeable pins and needles and joint pain in hands. I woke up at midnight with increased foot and hand pain and heat sensitivity and gave myself a shot. Another shot at 7 am mon. Throughout mon/tues i would have rotating pain throughtout joints, shooting pain deom elbow to hands, barely lift my arms due to significant joint stiffnes, and burning pins and needles and shooting pain in hands and feet which increases with heat and lying down ( which may be bduw to the heat-warm bed?). Tues i had my diest significant foot attack. Unbearable pain for 30 min. It repeates hours later. On a friends requet, i tried ice cold water- it seemed to shock the nerves ans the pain halte after 20 seconds. Oddly, after the initial cold shock, my feet felt warm-like the bottom of the bucket was heates? Anyhow. Could walk!!! It lasted 45 minutes before it came back with a vengeance! By then i was at the beach and walked in the surf! Relief!
    Unfortunately, again, another attack on both feet and while cold water helped somewhat, it couldnt take away the lingering joint pain and bruised feeling. Feeling a pending attack wed night, i went to ER where it progresses to intolerable pins and needles burning pain, joint pain in hands and feet (everywhere else still hurts – knees, shouldrs, etc). Anti-inflammatory IV-no effect until they just doped me with morphine. The after-effect if these attacks and progressively worse pins and needles in my thighs, buttocks, feet, hands. Etc leave my feet feeling bruised and broken, thighs feel bruised, knees are cripplingly sore. Still heat sensitive but finally manages to sleep through (mostly) the night thurs with no attacks. I can still barely walk and have the stiffness and bruising. The heat sensitivity is a bit decreases. They just started me on Lyrica. I had one dose late last night and one this am.
    So -does this sound like it could be b12 still or related but in fact precipitates by something else? My b12 was normal the first time and of course, i had given myself shots before the first round of b12 so it was high in that and subsequent tests.
    No inflammation markers though they did not test sed rate. All other routine bloodwork normal. Not lupus. ??? I’ve never read of anyone with b12 having these sudden acute episodes? Has anyone experienced this? Perhaps exercise/stress and some other compounding factors (celiac related) cause an acute reaction below a certain tipping point? Or that tipping point causing some other reaction to precipitate? Have you ever heard of this??? There are a battery of new blood teats including MMA i think, being done now…,

  83. Robert urmston says

    most of what I’ve read is about b12 deficiency. My two year old girl who has been clinically diagnosed with autism has been found to have a spike in her b12 when her bloods have been taken twice in the last year. Nobody can give a straight answer for this every talks about the deficiency side but never the opposite. when her bloods came back today for her age etc, her b12 count in her blood was 1165 when in should of been between 700 -750 . they don’t know why as she doesn’t eat very much and its hard to get anything down an autistic child who doesn’t like what you’ve made she sooner go hungry or graze through the day. Please can somebody explain why this how it is?

  84. Sam says

    I am interested in B12. But I also read that really high doses are not proven to be safe.
    Can you overdose on B12? Can you take 1000mcg daily forever or only for a while?
    I also wonder if B vitamins are water soluble then does this not mean that taking high doses
    will simply be excreted by the body?


  85. Lily says

    A BBC article about the new study on red meat/carnitine that has attracted a lot of media attention (published April 7, 2013) gives the following warning, and I’m wondering what to do with this information:

    “….I would strongly recommend that unless you’re a vegetarian or vegan, there is a potential risk from taking L-carnitine, lecithin, choline or **betaine** supplements in an attempt to ward off cognitive decline or improve fat metabolism. If the evidence is confirmed, these supplements would do more to damage arteries than provide health benefits.”
    from: the BBC, 7 April 2013, Red meat chemical ‘damages heart’, say US scientists http://www.bbc.co.uk/news/health-22042995

    I was just about to order a betaine/TMG supplement today, as per Chris’ low-B12 advice (taking 4 supplements: methylcobalamin + folate + TMG/betaine + potassium), when I saw this BBC article warning against taking betaine. I don’t know if I should just take the other 3 and skip the betaine?

  86. lindsay says

    Hi Chris (or anyone that knows),

    I am wondering about the MMA test. I have previously only taken the serum B12 test which showed elevated B12 which along with symptoms caused me to suspect a functional deficiency. Although I have been supplementing for a few months I would like to take the MMA test just to be sure I am barking up the right tree. Do I need to cease B12 supps for a certain period of time before taking the test? Thanks!


  87. Lucy says

    Chris, can you advise me please?
    My husband is 57 and suffers from lots of symptoms – all treated individually by different specialists for past 10 years. He has Ankylosing Spondylitis (an autoimmune disease), peripheral neuropathy in both feet (numb and tingly), a standing tremor, wide gait, osteoporosis, irritable bowel, depression and memory loss. His serum B12 was about 1900 and his MMA falls within normal levels. I am hoping to persuade my GP to refer him for an Active B12 test and Homocysteine – do you think it is worth it? Could he still have those results and not be processing B12 properly or am I barking up the wrong tree here?

    • Amber says

      Hi Lucy, Is he taking any Magnesium? I know low magnesium can cause systemic and wide ranging problems. And it’s an easy mineral to become deficient in due depleted soils, etc.

  88. Points says

    @jaqueline I used 23andMe for MTHFR. I’m from Canada and I don’t know if you can access from the UK.

    FYI I’m using a naturopath now who is B12 savvy. GPs and specialists are generally out to lunch in this regard. He has created a “cocktail” injectable containing B1/6/12 5-MTHF + some other stuff.

    Best of Luck!!!

    • Lily says

      I believe that people in the UK can order 23andme tests. I think I saw information about placing international orders on their website (23andme.com).

      I am thinking about ordering a test. The price is now permanently $99, much lower than it was a few years ago.

    • Lindsay says


      Where on the 23andme test is the MTHFR listed? I can’t seem to find it.. but if you do any reading on Phoenix Rising or anything people seem to be seeing a lot of stuff on their 23andMe that I am not seeing. Any advice?


      • Lily says

        Hi Lindsay,
        I tried to post for you 5 internet links to explanations that I’ve saved about MTHFR and how to figure it out with the 23andme test, but this site didn’t let that go through. Maybe they have a policy about hyperlinks to other sites. I’ll try to type it out in words, so you can find them online.
        a. look for the “genetic testing and snps” forum on phoenix rising
        b. look for the 23andme forum on the mthfr -period- net site
        c. look at the site called snpedia
        d. look at the US goverment site on genetic testing at
        ghr -period- nlm -period- nih -period- gov -backslash- gene -backslash- MTHFR
        e. look at the mthrfsupport website under the nov 2012 article about 23andme

        • Lindsay says

          Hi Lily!

          Thanks so much for your efforts and reply. I finally figured it out yesterday and low and behold I am compound hetero for both of the MTHFRs that matter. I feel at once relieved that it is not all in my head and discouraged after reading so many horror stories with how those mutations relate to failed pregnancies. Oh well.. I will keep on keeping on and will be certain to not just randomly stop taking the B12 and folate supps like I had in the past!

          Thanks again,


  89. Jacqueline says

    Hi chris, I was diagnosed with b12 deff a year and half ago, this was after approx 10 – 12 years or more of going to and thro to GP with many symptoms, mainly to be told its all in my head or look at me as though I was mental and making it up. Finally my b12 was tested and was 133 and low folate (don’t recal the results) I had b12 jabs once a week for 10 weeks the first 5 was cynocolbamin and the next 5 was hydrocolbamin (sorry if not spelling these right but think u will all know wat I mean) then week after my last jab my bloods was taken and test results for b12 was 886. GP then stayed I only needed jabs 3 monthly as my b12 levels was now very high, just to add that after about the 6 week of having my initial 10 jabs I was starting to heal and this continued as by the 10th week I was so much better not perfect but a lot of symptoms had eased a lot. Part way through week 2 of not having a b12 jab I was starting to get symptoms back to the point that end of week 2 symptoms seemed worse than before I started jabs. Went back to GP and although I got him to agree to give me another jab and also agree to give me them monthly he did not agree that my symptoms could be b12 related. I had 1a month for 3 months then bloods tested yet again this time b12 at 931 so again GP wanted to give 3 monthly even though I stated that I was just about dealing with the monthly jab as week 2 symptoms all back with force. Agreed on 2 monthly but also sent me to see rheumatologist and neurologist. Rheuma said possible fibromyalgia but only once all other avenues had been exhausted and neuro though it to be hnnp but shock tests stated different. Neuro said in end he thinks symptoms vitamin related. I hav had tests twice for PA but negative. I possibly have nearly every b12 symptom listed and same with fibro as they are very similar. GP have now diagnosed me with fibro just over 5 weeks ago. She one of the younger GP today as meds for fibro not working he is in the same mind as me as is it fibro or b12 he seemed bit sceptical it being fibro. I just wish I get a firm diagnosis so I can at least hav a name for wat I got. I hav asked over and over for active b12 test and but they ignore me. I would like to know if anyone knows if the MTHFR mutation test is available in the uk as I hav been told on sites that should test for this and also if MMA test is available in uk as I do not want to ask GP for these and for them to think I hav gone mad. Just to add my sister b12 is 33, and several other members of family hav low b12, my mums is 220. My 3 older children are showing symptoms but not tested and my 6 year old daughter is showing a lot of symptoms but they refrain from testing her and say its calcium and to give her more but I’m so certain it’s b12 and would like to jump on it ASAP if she has. Look forward to hearing from anyone x.

    • Becca says

      Your story sounds very similar to mine! I am sorry you are having to go through all of this! Have you asked your doc for the MTHFR test? I didn’t even know the mutation existed until my Internist asked if she could test for it after years of low b12 and other symptoms. I have since learned of the 23andme testing, but I got mine through a regular medical lab and ended up not paying a dime after insurance.

    • Lily says

      Jacqueline, I believe that people in the UK can order 23andme tests. I think I saw information about placing international orders on their website (23andme.com). The price (before shipping & handling is added in) is 99 US dollars (around 60 British pounds or so). If you wish to order a test on one or more of your family members at the same time as you order your personal test, they give a discounted rate.

      There is a video on youtube.com of a BBC regional news program about an NHS doctor who was diagnosing some of his patients with low B12 and giving them frequent injections, and he was investigated by the General Medical Council (or some such body) and stopped from practicing for a time. He had to jump through all kinds of hoops to prove he was not doing any harm and that he was doing something medically valid.

      • Jacqueline says

        Hi Lilly, yes I know of this doctor and have spoken to him. He offered to send me down the American B12 vials which he said is so much better than the one my doctor is giving me but that I had to get my doctor to give his permission for this but my GP states he cannot due to insurance reasons. I would go to use this GP but he is at the other end of the country. I have also asked about the MTHFR test but having active b12 test done first (of which I had to get referral from my doc but I have to pay for) then they will talk to me about the MTHFR test.

    • Judy says

      I started showing symptoms of tingling and numbness in my toes 8 yrs. ago. Neuro’s thought I had MS, but MRI’s showed I didn’t. Then they thought it be fibromyalga, but no. Two years went by before a dr. took tests and found out my B12 level was 41. By then there was permanent nerve damage. My legs and feet have spasticty, stiffness, spasms and my balance is bad. I have to use a cane and/or walker since I’m a fall risk. People out there laugh when I tell them it’s from a B12 deficiency. I had to go through monthly series of b12 shots for years. But the past few years I found a nasal spray of b12 called nascobal and you take it once a week and my level has been in the 700’s.
      Now anyone out there interested in nascobal should consult their dr. cuz he/she may not recommend it but it works for me and no more shots!

  90. Lily says

    Hi Chris,

    Just a few suggestions in terms of helping readers find this second, more-recent blog post on B12:

    I first visited your site about two weeks ago for a short while, and at that time I skimmed through a number of your article titles, noting that you’d written two B12 posts (the one from last year, the one from this year).

    Today, I tried to find the two B12 posts again by using an internet search engine to search for “Kresser” and “B12″, and only the earlier post came up. So I went to that post and clicked on your internal topic classification tag of “B12″, thinking that your second post would also have been assigned that tag, but under your classification tag of “B12″, only your first post is listed on your site. I then went to your site’s search box and typed in B12, but I don’t think that it came up that way, either. I was starting to wonder if my brain fog was tricking me into thinking that you’d written two posts on this topic, though you hadn’t! I think that, in the end, what I had to do was go back out to a generic search engine and find a link to this post via a mention on someone else’s paleo blog about your views on B12!

    Because I believe that this 2013 follow-up post adds a lot of value and is good to read in conjunction with the original 2012 B12 post (which is one of your most popular posts, I note), I would encourage your web team to associate additional, relevant tags (like “B12″) with this post, to directly mention the existence of this follow-up post at the end of your first B12 post (and include the hyperlink there), etc.

    Not only is it helpful to the reader to learn the contents of both posts, but I think you only mention your 4-supplement protocol in the second post (which is the information that I was trying so diligently to re-locate today!), and you may want to put an addendum paragraph in the first B12 post to give your 4-supplement recommendations — and to supply your Amazon links — directly on that page, since it’s a more highly-trafficked article.

    FYI –
    First one is tagged as: b12, cobalamin, deficiency, epidemic, vegan, vegetarian
    Second one doesn’t seem to have any tags (?)

    By the way, I’m not sure why (maybe it’s the nearly-1000 comments), but that first B12 post takes a long time to load on my computer (although I have a fast internet connection) and it sometimes freezes my Internet Explorer (whilst no other page on your site seems to do that). Either that happens, or I get a warning window saying that a script on the page is taking too long to run and do I want to cancel it. This will also unwittingly detour readers away from that page. Maybe it’s something easy to fix by the technical folks?

    Thank you for your generous sharing of information and your extending of caring help to people, not only on this site, but also in the wider world. :-)

      • Lily says

        Hi Laura,

        Thank you for responding!

        Unfortunately, the tags do not seem to be here on this post.

        Even though I still can’t see any tags here, I thought that maybe they were associated with this post but just “silent”, or maybe they were really on this page and I was simply overlooking them (which is definitely possible!), so I went over to your first post on B12 (which earlier I had said was published in 2012, but now I see that actually it was published May 6, 2011) and clicked on the “b12″ tag that appears at the end of that post (it’s in this line “Tagged as: b12, cobalamin, deficiency, epidemic, vegan, vegetarian”) and unfortunately, what comes up under the B12 tag is only that 2011 post. So there seems to be a technical issue with the tagging.

        I don’t mean to harass you about this – it’s not for my sake, as I have the posts saved in my Internet Favorites. I am only letting you folks know this because many casual visitors to the site who read the first B12 post will have no way of knowing that Chris wrote a second, updated, advanced post about B12 twenty months after he wrote the first one, and that he provided in the second one a suggested set of supplements to take, which he did NOT do in the first post.

        The comments section of that first B12 post is still going strong (even this week there have been several new comments there), but the majority of the people who participate in those comments probably do NOT know about this second post which provides Chris’ updated thoughts on B12 and provides, for the first time, Chris’ suggested B12 supplementation routine. And even if readers of that post search Chris’ blog to see if there are other posts on B12, this second post is not listed in those search results.

        Also, just for the sake of the site’s earning potential, it would seem beneficial for you to allow site visitors to learn about your suggested 4 supplements for B12 replenishment and to have access to your Amazon hyperlinks to them, so the visitors, if they so choose, can use those links to buy the supplements, giving your site a small cut from the retailer in the process.

        • Mark says

          Hi Lily,

          Thank U so much for your generous and valuable input to these posts.

          Like many others I was completely unaware of this 2nd post and did in fact recently post on the previous one- seeking for help in fine tuning my supplement regime.
          Thank U for posting on the 1st article + over here to alert us all- U R a star!

          Would highly recommend that Chris himself writes a comment on the 1st post to let everyone know that he has a second article & one that states some of the other supplements to be taken together with Methyl Cobalamin B12 sublinguals.

          On another note- its the 1st time Im reading that we need Trimethylglycine!?!

          Last week I started taking B12 Enzymatic Therapy 1/4 tablets (ie 250mcg) + Solgar Folate 1/2 tablet (ie 200 mcg) in addition to a Multi Vitamin & 2 Bananas daily- but after just 4 days I felt drained from the lack of good sleep! Im B12 & D Deficient & my recent Bone Mineral Density DEXA report indicates I have Osteoporosis at 41 years old despite a very active exercise & balanced diet regime!

          TKS & God Bless U,

          • Felicia says

            Yes, so thankful Lily pointed out this second post, and I second all of her suggestions above to get this one in the radar of readers. I have read every comment on both posts and it’s clear there are many, many people out here who have this issue and can use this very valuable information. It has helped me in so many ways, I can’t thank you enough — both the information itself, the suggestions that were applicable to me, and the connection to others who have a lot of experience with this issue. Thanks!

          • Holly says

            Mark – are you celiac? Celiacs are commonly deficient in B12 and of course, prone to osteporosis (many of whom dont know they are celuacs until they are diagnosed with osteo).

          • Lily says

            Mark and Felicia,
            I’m so glad that my notice on the other thread helped you to find Chris’ updated B12 recommendations (and the further reader discussions) on this page!

            This is just a conjecture, but it sounds as if you may need more potassium than what 2 extra bananas can provide. That feeling of fatigue/needing to sleep a lot might mean that your potassium has been all used up by the methylation. Potassium is available in many stores in 99 mg tablets, and you can also order tablets of larger milligram quantities online (for example, from amazon, swansonvitamins.com, etc.)

            About the TMG/betaine component of Chris’ 4-supplement recommendation, please see my comment further down this page quoting a BBC article from 7 April suggesting that standalone betaine supplements may cause health problems. I am hoping that Chris will address this claim, either in the reader comments here, or in the reader comments under his “eating red meat” article/blogpost that he published a few days ago.

  91. Deborah says

    I’m having trouble with the Jarrow subling b12 5k. That area under my tounge feels very raw and almost burned. Any suggestions for different brand? Has this happened to anyone else?

    • Lily says

      Deborah, I have read on another forum that this supplement and ones that are similar can do this to people’s mouth tissue, and they also can erode nearby tooth enamel, because of citric acid and other non-active ingredients these lozenges are made with (in order to make the taste more palatable, I guess).

      I have a bottle of Natural Factors B12 methylcobalamin sublingual that has no flavors, colors, citric acid, artificial sweeteners, etc. (I think that brand might also have B12 sublinguals of the same dosages, 1000 and 5000 mcg, that do have that extra stuff in them, so read the labels carefully if you are thinking of purchasing these). I am very pleased with it, in terms of not affecting my mouth tissues or my teeth, but I have gotten the feeling from reading various discussions in various forums about B12 deficiency that the Natural Factors methylcobalamin is not very highly regarded (in terms of its perceived potency) by experienced users of B12 supplements (such as Freddd and folks who swear by his B12 replenishment protocol).

      Before I had come across Chris Kresser’s 2 blog postings about B12 or the other specialist websites that go in-depth about B12 replenishment (and thus I didn’t yet know that there are several supplements that should be taken ALONG WITH full-strength methylcobalamin), I had been taking a 1000 mcg tablet of the Natural Factors methylcobalamin daily for 2 weeks with no problem, and the first steps of healing were really seeming to take place (in terms of my particular deficiency symptoms), but then I suddenly had a “potassium crash” that put me out of commission for about 36 hours (constant heart palpitations, lasting muscular cramps in my back and neck, feeling totally drained), which I guess meant that the methylcobalamin in the Natural Factors must have been doing *something* powerful in my body!

      I tried to find out what was happening to me and discovered that this kind of crash was common with methylcobalamin (this potential potassium imbalance, called hypokalemia, is even mentioned on the Wikipedia page for B12 deficiency, which I had actually read before I started taking the B12 supplement, but I had just not paid enough attention to that part). I rested, ate as many foods as I could find in the house that are high in potassium, and stopped taking the B12 until I could get some potassium tablets locally. (I’ll have to order the other two supplements online because they are not available where I live).

  92. becca says

    After years of b12 deficiency, I have a new doctor that tested me for the mthfr mutation. I tested positive for a compound heterozygous mutation. I’m learning info as I go. I’m now on methylfolate and methylb12. Can you give any nutritional advice? Also I’ve read a lot on epigenetics…is thissomething I can “turn off” after proper methylation supplements?

  93. Paul says

    Hi Chris,

    I have MS but I inject B12 every 3 days because if I don’t I crash – numbness in hands, fatigue, worsening of spasticity and gait issues. Serum level at 1400 and doc thinks I’m crazy. MMA came back negative but clearly I have a B12 problem as I experience big improvements in numbness, spasticity, balance etc. Help!

    Thanks in advance, P

    • Aliz says

      What about your vit. D level? A friend of mine who has MS does the same thing with vitamin D, every day like 5000UI. A famous London neurologist prescribed it for her after a bad attack, and she’s okay, her recent brain scan showed no declension.

  94. Shashi says

    I am 8 weeks pregnant with my second child and keep waking up with tingling and numbness in my hands. I had this problem while nursing my first as well. I was vegetarian/vegan for 15 years. My B12 tests have always been on the lowest end of “normal”, so I guess I’ve been deficient for a long time. Are there any special supplementation considerations I should make while pregnant? Or will the recommendation above work for me?

  95. Amy says

    Hello Chris,

    I’m very glad to hear that sublingual B12 is better than injections. I used to get injections and then developed reactions to them. I would break out in cystic acne about a half hour after and I now think this might be do to with my histamine intolerance. As I understand it, B12 can raise histamine levels. If this is the case, would sublingual be better for me since it is not as concentrated?

    Thank you

    • Felicia says

      My sense of what Chris said was that sublinguals work better for some people than injections — I’m not yet convinced that they are 100% better for everyone based on my own experience, what I’ve learned from practitioners, and what people are saying here. For one thing, some people react to the other ingredients in sublinguals and some do well with injections while others do not, does that make sense? My sense is that it is a highly individual situation, but it is well worth being open-minded to all the options.

    • Sheena says

      Hello Amy! I also developed cystic boils on my forehead after getting B12 injections. I would like to hear more about your health history. I have been gluten free for 4 years (per a genetic test), hypothyroid, anemic… Maybe we could help one another. :)

  96. says

    About a year ago I was eating a mostly vegan diet after being a vegetarian for a year. As soon as I learned vitamin B12 was only found in animal products, I sought out a supplement. While I eat pastured meat every 2 weeks and consume eggs almost daily now, I still like to take my supplement because I am sure I have some catching up to do, if you will. I take a SISU 1000 mcg methylcobalamin tablet daily, normally with a meal. However, I am wondering if I should be taking this pill on an empty stomach? I have had some low stomach acid lately (not new to me), which I am working on (this is actually how I came across your site), and was worried that if stomach acidity is important for B12 supplement absorption, that I may not be absorbing any of the supplement. Does it matter if I take it with food or not? and is stomach acidity important?

  97. jose says

    Heya Chris,

    I don’t eat meat, but would prefer as much as possible to get all my vitamins and minerals naturally – what would be the most effective way of getting sufficient B12 while eating as little meat as possible?

    I have been considering eating wild game, in the form of Biltong once in a while. I tried this a couple of years ago and was very ill – it had been quite some time since I ate it, but maybe less for the first time next time! How much do you think I would have to eat each month to give me the required amount of B12?



    • Chris Kresser says

      Jose: clams, oysters, mussels and liver are the most concentrated sources of B12. 3 ounces of clams is equal to 1,401% of the daily value (DV) and 3 ounces of liver is equal to about 1,214% of the DV. So in theory one 3-ounce serving per week of either of those would be sufficient. (However, that’s assuming optimal absorption, assimilation, co-factors, etc. — which is often not a safe assumption.)

  98. Melanie says

    Dr. Chris, Do you have any articles on the types of meat that are best for b12 and how often to eat, of course it would be a generalization. It would be nice to have a basic understanding of what is average to compare and contrast with my current diet.


      • Jordan says

        I’m a 31M and just started having peripheral neuropathy and quad weakness for the last two months. I also deal with lots of anxiety and heart palpitations. Since my symptoms started, I’ve tried acupuncture, liver cleanses, juicing, more raw foods, removing a newly purchased memory foam topper, and and started supplementing with multi-vitamin, Nordic Naturals Ultimate Omega, 5-7 k IU of Vit D3, and magnesium. I *just* started 200 mg of Doctor’s Best stabilized R-Lipoic acid.

        I even bought a glucometer to test my after meal blood sugars (my fasting blood sugar had been 90 twice, was 83 recently and my hemoglobin a1c was 5.4.) After meal blood sugars never went over 140 over a week of testing so it doesn’t sound like high blood sugars.

        My Vitamin B12 level was 679 PG/ml, my folate, RBC is 364 mg/nl and my Vitamin D was 24 ng/ml. Been tested for Lyme, sjogren’s, lupus, gluten intolerance, etc and all came back negative.

        Could it be a b12 and or folate deficiency all along?

        Any suggestions Chris? Love the blog!

  99. says

    Dr Chris,

    I am 61 and not taking any meds and supplement with methlylcobalimin, TMG, and folate, among other things. I eat eggs and/or meat every day. Yet my homocysteine levels are elevated at 13 umol/L. My weight is normal and I also exercise. Any suggestions on how to reduce homocysteine?

    Thanks, Michael

    • Peter-NZ says

      Vit B6 (pyridoxine) disposes of homocysteine, B12 and folate just cycle it back to methione from which it is formed.

  100. Mary says

    Hi Chris, a friend pointed me to your site. A few years ago I had a near-fatal brain trauma (“died” and later “came back”) and have not recovered. At the time my neurologist said there was nothing nutritionally that would help. I have not recovered and have some level of brain damage, as well as quickly degenerating nervous, endocrine, immune, and musculoskeletal function, as well as have body-wasting. Probably more issues, these are just most obvious. Have seen nearly 100 specialists/doctors/nutritionists/alternative practioners/therapists and after they take the “well-intended” stab at diagnosis and treatment, they have all ultimately just called me humpty-dumpty. Starting in 2009 I followed the Clean Program religiously for a few years, did the fresh juicing, smoothies, proper calorie management, and supplemented to the very best I could, given advice and impairments. And it ended up have no beneficial effect. My body does not seem to tolerate or digest anything anymore. At some point, do you advise we just throw a hail-mary and hope for the best? best.

    • David says


      Check this out: http://www.ncbi.nlm.nih.gov/pubmed/23100196

      Not nutritional therapy, but appears to be acting as a “good” drug in this case because it is improving symptoms by improving function. Google a bit more about this. In some cases, long-lasting results (years) are achieved in as little as a single injection, even in cases of up to 10-year old brain trauma. Worth considering.

      • Mary says

        David, appreciated. Good to see trials underway and will discuss next time visiting doctor. As far as B12, was taking before and ordered some to try again, then will see. Maybe it will help some. Best to you.

  101. Chris says

    Chris, My family eats a mostly vegetarian diet, except we eat alot of pastured eggs. I want to make sure we are getting the vitamins and minerals we need. What kind of supplements do your recommend for people like us, and where’s a good source that we can trust to tell us exactly what nutrients a body needs–children as well as adults?

    • Chris Kresser says

      B12, iron, zinc, retinol (active vitamin A) and EPA/DHA are the most common nutrients vegetarians are deficient in.

  102. Victor says

    Chris first and foremost thank you for the info you provide. How do we keep the more natural approach to medicine and raise the standards of the current Doctors.

  103. M says

    I have the MTHFR variant. I know because in Sept 1999 I developed a blood clot. I was 35 at the time and had not been married a year yet.
    I was on coumadin for 2 1/2 yrs and hemorrhaged.
    I have been doing the supplementation ever since with B complex and extra folic acid, B12, B6 , E, Magnesium, Fish oil, zinc .

  104. Jens says

    Hi Chris,

    Do you ever see recovery of patients with peripheral neuropathy due to low vitamin b12? Is there anything else one can do besides normalize b12 levels to try to recover? Thanks

    • Chris Kresser says

      Hi Jens: yes, I have in quite a few patients. It’s definitely worth a try. You may want to read up on methylation defects and check into either Rich Van Konyenberg’s or Fredd’s protocols. Google them; they’ll come up.

      • Lily says

        Just a note to say that Rich and Freddd’s protocols changed over the years, and several versions of them are still on the internet, in discussion threads that can be very long, with people still contributing to them years after they were started (and it’s all so complicated anyway, at least when you are new to this subject like I am!)

        Therefore, be careful when looking Freddd and Rich’s recommendations up on internet search engines — try to find the most recent version of their protocols.

        I may be wrong, but as far as I have discovered, these are the most recent versions:

        Rich’s: http://forums.phoenixrising.me/index.php?threads/revised-simplified-methylation-protocol-august-25-2012-revision.19050/
        [Note: Sadly, it seems that Dr. Van Konyenberg passed away a few months ago, so this is the last version of his protocol.]

        Freddd’s: http://forums.phoenixrising.me/index.php?threads/the-stages-of-methylation-and-healing.21725/
        (note: That specific thread by Freddd is quite complex and technical, and I do think there are shorter descriptions around of his current B12 thinking – I’m not able to find a concise one right now though. Do make sure to look for posts by him that are from the last couple of months, because he has changed some of his hypotheses and some of his product recommendations relatively recently.)

  105. says

    I had suffered from depression and anxiety since I became a vegetarian, and then being paleo only helped my symptoms slightly. I started supplementing with Nutri-Dyn’s Phytomulti multivitamin, which contains a high dose of methylcobalamin and this has made a huge difference. A chiropractor had previously had me supplementing with cyanocobalamin and this caused my serum levels of B12 to skyrocket to way above the desirable range, but my symptoms didn’t improve, potentially because I have methylation issues and was not absorbing any of that type of B12. The methyl- type definitely helps some of us while the cyano- version does not.

  106. Tami says

    Hi Chris,
    Thank you for the article. Is there any harm in supplementing with B12 at your recommended maintenance dose for a ‘trial’ without lab confirmation of deficiency? I am paleo (PHD-esque) 1+years but was a veggie for a couple of years prior…

  107. Shirlee McCourty says

    Hi, Really interesting article. I have been diagnosed with Hypermobility Syndrome, Fibromyalgia, severe IBS & also am Hypothyroid. I had a blood test Sep 2012 that should very low B12, doc wanted to give me injections but I really did not want to go down that route every 3 months! so I started on Jarrow Methyl B12 sublingual tabs and noticed a difference after a couple of weeks. Recent blood test showed B12 now back to acceptable levels (whatever that means lol) I still take them daily with my thyroxine and a multi vitimin tablet for the over 50’s..While I cant claim they are a cure all. They can’t for example address pain and mobility problems, but I feel much more alert mentally than before. so will continue to take them.
    Incidently my Mother also had years of neauralogical problems before being diagnosed with MS at 50 with no remissions, and sadly died at 60. I wonder if B12 could have helped her as she also had Dimentia linked to the MS, and I have heard that a lot of elderly people with Dimentia are Vit B12 deficient?

  108. Jared says

    I’ve heard taking methylcobalamin can cause problems with people with MTHFR mutations. I have a double mutation so im A1298CC, but when I took methylcobalamin it made me feel even spacier, it was 5,000 mg which is a lot though. I’ve been taking hydroxycobalamin sublingually, about 1,000 mg and it seems to help some but think maybe taking shots or lower dosages over time might help. Im waiting until I get results from my 23andme test to see what SNPs I have besides MTHFR, since that can determine what form would be better to supplement with.

  109. Leaf Eating Carnivore says

    Chris –
    If you link to Quest’s site, and go to their lab locations page, you will find that the lab in Indianapolis lists the VitB12 HOLOTC test, which assay is actually performed in Valencia, CA, if I read it right. Seems to me that if they have the wherewithal to do the analysis there, should be easy enough to send the sample from any of their draw locations – yes/no?

    • Honora says

      I believe it would be. Our lab’s active Vit B12 test requires the plasma or serum to be spun off, then kept at 4 degrees Celcius (about the same as a fridge) then it is considered stable up to 7 days after this.

  110. Chuck says

    Great article Chris!

    I actually did the blood test you mentioned above and my B-12, along with my Pantho (B-5, I think?) was low as well. I am working to improve my diet to amend this deficiency, but I also started a supplement today, taken after breakfast and lunch. I really did feel better and more energetic today, but I noticed my urine was bright yellow, even though just starting this morning. This makes me think I’m not absorbing the vitamin, yet I feel as if it has given me a lot of energy. So should I be worried about the bright urine color?


  111. Megan says

    Hi Chris,

    A quick question about B12 testing and the standard complete blood count test. I frequently test as having mildly elevated MCV (around 98) and mildly elevated MCH (33.6 was the highest). These are usually just barely out of the reference range, and my doctor is not at all concerned. I’ve read, though, that much higher readings could be indicative of deficiencies in various B vitamins. In general, do you think such mild elevations are indicative of deficiencies?

    Thanks for all you do! You have been so very helpful to me in my quest for better health.

    • Chris Kresser says

      Yes, elevated MCV is often a sign of macrocytic anemia. Red blood cells actually start out large, and as they mature they become smaller. That maturation process requires B12 and folate. The mean corpuscular volume (MCV) measures the average size of the red blood cells; if it’s high, it suggests the red blood cells aren’t maturing (getting smaller), which is usually caused by folate or B12 deficiency (more commonly B12).

      That said, a few other conditions like hypothyroidism can also cause elevations in MCV. I would definitely get your MMA checked, along with serum B12.

      • Felicia says

        Megan, I too had mildly elevated levels of MCV and MCH and was diagnosed with pernicious anemia a couple years ago, so I agree with Chris about the testing if you haven’t done it yet. I just did follow up tests last week and will be meeting with my practitioner this week — and I’ve been on B12 injections for two years, too. It’s like night and day for me energy wise, so I am so thankful my practitioner discovered this and this website is here for further information!

    • Honora says

      Our lab won’t test B12 without also testing folate levels as a reduced Vitamin B12 level can be masked by folate deficiency.

  112. Hannah says

    Hi Chris,
    Can you please tell me if the B vitamins from kombucha are absorbable? I’m guessing they may be similar to what is found in brewers yeast. I have always considered kombucha to be a valid source of b12, I’d really love to know if that’s not the case.

  113. Michelle says

    Hey Chris what would you recommend for vegetarian children? I have an 8, almost 9 year old, who has never eaten any animal products except milk and cheese. He absolutely refuses. Gags, even as a toddler. I have given him iron supplements but his bloodwork always comes back on the low side.

    • Chris Kresser says

      Methyl-B12. I’d say maybe 200-300 mcg, but check with your doctor. The co-factors will also be important for him.

  114. says

    Hi Kris. I’m from New Zealand so sometimes translating American stuff to what is available to us is tricky. I’m hoping I can find someone here who understands about B12. I’ve had Bells Palsy for 11 months. My nutrition is generally good and I supplement with vitamin B complex with extra B5. I take a Nordic cod liver oil and eat grass fed beef etc. My B12 showed normal to high on blood tests but I understand B12 might help heal the nerve sheath or myelin. I still have active Herpes Virus but my doctor seems totally unconcerned.

    I am thinking about going to a natural health doctor but feeling cautious as this will be costly.

    Any ideas.

    • Sheridan Jackson says

      MargieAnne: I have read that benfotiamine, which is a lipid-soluble form of B1, can cause regeneration of myelin. See benfotiamine.org.

      • says

        Thanks for this. I am searching through and will probably purchase a supplement with benfotiamine. Nothing like experimenting on myself but at least it seems exceedingly safe.


  115. Kevin says

    Chris, do you have any thoughts on the work of Dr Amy Yasko regarding methylation and B12 supplementation? She might be an interesting podcast guest. She has some interesting theories associating certain SNPs with over/under methylation, MTHFR, autism issues etc.

    To those feeling fatigued by taking B-complex vitamins. I used to feel low energy after a couple of days of taking methylated b vitamins, and after reading her work and looking at my SNPs, I switched over to hydroxocobalamin and there was no fatigue despite daily supplementation. Yasko associates some COMT SNPs with tolerance of methyl donor supplementation.


    • Chris Kresser says

      I’m aware of Dr. Yasko’s work, and I agree she’d be a great podcast guest. I’ll ask my producer to look into it!

  116. David says

    Can people get start up effects when they commence taking activated B vitamins. By start up effects I don’t mean over-methylation, but feeling unwell due to the long dormant biological processes coming back on line and perhaps causing the shift of toxins.

    Also, do you think that adenosylcobalamin is worth taking as a supplement?

    • Chris Kresser says

      Yes to your first question. And yes, some have better results with adenosyl. Those with methylation defects may need both methyl and adenosyl.

      • Eve says

        This is good to know – thought maybe I could not tolerate methylB12 and bought adeno. So these “start-up effects” mentioned – I am assuming this is detox. Would this cause toxins to enter breastmilk?

        • Deborah says

          Start up and detox are totally different things – start up is where you give your body fuel it didn’t previously have and all of its processes speed up which can be uncomfortable until everything settles down. it also means that you can run out of other vitamins and minerals as the B12 uses them up. Most notably potassium. for me start up involved really bad headaches, the jitters and a few mood swings. i drank a lot of coconut water as its high in potassium.
          incidentally, adenob12 works on a cellular level while methylb12 works on larger organs and in your bloodstream.

  117. Emily says

    Chris are the supplements you refer to safe and beneficial during pregnancy (obviously I’m already taking solgar folate as part of your healthy baby code)?

  118. Chris Kresser says

    Folks: just added some important information to the testing section:

    There are two ways to have MMA measured: in the serum, and in the urine. (4) Each has advantages and disadvantages. Some experts believe that urinary MMA is superior to serum MMA as a marker — possibly because it is more concentrated in the urine than the blood. However, elevations in urinary MMA can also be caused by kidney dysfunction. (5, 6) On the other hand, serum MMA can be elevated in the presence of intestinal bacterial overgrowth. (7). Therefore, which test you choose should depend on your health status. If there’s any question of impaired kidney function, serum MMA would be a better choice. If you have or think you may have SIBO or gut dysbiosis, urinary MMA would be the better choice. Quest, Labcorp and many other labs offer both serum or urniary MMA, so you shouldn’t have any problem getting it provided your doctor will order it. Note that you need to be fasting for the urinary MMA to get an accurate result.

  119. says

    For those interested in testing their B12 levels, it’s one of the tests offered in Talking20’s “vitamin pack.”


    I can’t vouch for the type of B12 test they offer, as I have no affiliation with them. It just seems like a great option for us health-conscious people to stay on top of what’s going on in our bodies without inconvenient and sometimes very pricey doctor visits.

    The campaign is over at the end of Sunday, Jan 20, so not much time left.

  120. Chris Kresser says

    Hi everyone,

    I just found out that Quest is not, in fact, offering the holo-TC test yet. It’s listed on their website, which is what led me to believe it’s available. However, they aren’t offering it at any of their Quest blood draw locations, which effectively means it’s not. Hopefully someone will get on this soon!

      • Sarah says


        You posted 5 months ago, so you may not see this, but I’m surprised no-one’s mentioned NOW to you. I have a bottle in front of me (rather than a frontal lobotomy – tho, most days, it feels like I’ve had one of those, too!) and it states: –

        Contains no salt, yeast, wheat, gluten, soy, milk, egg, or shellfish.

        Ingredients: – fructose, sorbitol, cellulose, citric acid, stearic acid, magnesium stearate and natural flavours.

        Is that any good…?

  121. ali says

    I would like to supplement with B12 as I have been told by my doctor am I in the borderline low range (from more standard serum tests). I was given Superior Source – No Shot B12 Methylcobalamin Instant Dissolve 10000 mcg to take which includes Vitamin B6 (as pyridoxine HCl), Folic Acid, B12 as Methycobalamin and stevia extract. After a week or so of taking the supplement, I begin experiencing extreme agitation and worsening mood. The symptoms were pronounced and severe. Once I discontinued taking the supplement these symptoms resolved. Has anyone heard of this kind of adverse reaction while supplementing with B12?

    • Amber says

      I would avoid supplements with folic acid, it’s probably what you’re reacting to. Superior Source makes a B12 without the additional stuff…maybe you can try that?

    • Lily says


      What you mention might be due to the same thing that recently happened to me –

      Before I had come across Chris’ 2 blog postings about B12 or the other specialist websites that go in-depth about B12 replenishment (and thus I didn’t yet know that there are several supplements that should be taken ALONG WITH full-strength methylcobalamin), I had been taking a 1000 mcg tablet of methylcobalamin daily for 2 weeks with no problem, and the first steps of healing were really seeming to take place (in terms of my particular deficiency symptoms), but then I suddenly had a “potassium crash” that put me out of commission for about 36 hours (constant heart palpitations, lasting muscular cramps in my back and neck, feeling totally drained).

      I tried to find out what was happening to me and discovered that this kind of crash was common with methylcobalamin (this potential potassium imbalance, called hypokalemia, is even mentioned on the Wikipedia page for B12 deficiency, which I had actually read before I started taking the B12 supplement, but I had just not paid enough attention to that part). I rested, ate as many foods as I could find in the house that are high in potassium, and stopped taking the B12 until I could obtain the other 3 supplements that are meant to balance everything out.

    • Tanya says

      I’d suspect the methyl groups. Not everyone needs extra methyl groups–genetics, along with current health state, can play a big part in whether someone benefits from them. Agitation, ragey-ness and mood issues can happen if you consume methyl groups that you don’t need. A lot of people, like my family, do great with the extra methyl groups, but I’d look for a good hydroxy B12 supp in your case.

  122. MomLadyOR says

    Thanks for yet another fantastic article Chris!! I found this out for myself through trial and error. My multivitamin company changed their formula and I immediately had some constipation issues. I figured I just needed to adjust so give it a month. As the month progressed my brain fog got really bad and my PN returned to the point it was bothering me. I decided to find a different multi. The lady at the health food store suggested I find one with methylcobolamin so I did. After just one dose I noticed a huge difference!! Went from standing at the stove trying to figure out how to work it one day to feeling sharp as a tack again the next. My ND wants to do some kind of special blood work for B12 and other vitamins, because of my response to the vitamins. Can’t wait to get the results (although do to finances, it will be a month or so before I go). Oh, and I’m a big meat eater. Always have been.

  123. Beth says

    Is it dangerous to have a really high B12 levels (after following Paleo for a while, like I am)… Mine are almost 1000?

    • Chris Kresser says

      No, it’s not. B12 is non-toxic even at relatively high levels/doses.

      Over-methylation is a concern for those supplementing with very high doses of B12 over a long period. That should be done under supervision.

      • Beth says

        But I don’t take any supplements… I get all my B12 from the meats/seafood only. Does this mean I’m overmethylated and change my diet a bit?

      • Sharon says

        As with Beth, my last B12 serum test was 1039. It’s been over 1000 for a few years now, but docs never blink. I was worried as I read scary things about elevated B12 (leukemia, liver disease?).
        I also eat plenty of red meat (grassa fed, of course), pastured eggs, etc. I don’t pop B12 sublinguals too often. I decided to stop taking them when I noticed these high B12 levels.

        My other blood tests don’t really suggest anemia. Any thoughts?

        • pam says

          i was diagnosed w/ severe iron anemia a year ago. took 2 months of liver (2 oz) every day to become low normal. come to think about it ; i may have been in & out of anemia all my life.

          the interesting thing was my B12 was also high.
          my diet is between of PHD & WAP; i also dont’ take B12 supplements.

  124. jen says

    Thanks for all of this information. Do you know why so many makers of B-12 supplements (in all its forms) state that the supplements are vegan or “suitable for vegetarians”? Even the Jarrow Methyl-12 bottle says this. I just want to make sure I’m getting the right stuff. Thanks!!

      • Kristi says

        In the post you mentioned the only way to get B12 was from animals, but then this supplement is animal parts free. This doesn’t seem possible based on what I read?

        • Chris Kresser says

          The only way to get B12 in the diet is from animal products. The second way to get it is by supplementing.

          • Kelly says

            Chris, Great article on the importance of B12 supplementing…but why do you keep saying B12 is only derived from animal sources? I only ask this, because no mammal is capable of producing this vitamin in vivo…

    • Honora says

      It looks as though Vitamin B12 is produced commercially for supplements by fermentation of forms of starch using particular bacteria e.g. beet molasses as the fermentation substrate for industrial vitamin B12 production by Pseudomonas denitrificans.

    • Chris Kresser says

      Yes, though I’d pay attention if it were toward the high end of normal, since MMA doesn’t become elevated until Stage III deficiency.

  125. FleurdeLys says

    Hey Chris,

    It’s a little bit out of subject, but I’ve heard that yeast contains B vitamins, and so I was wondering if unfiltered beer (or beer on the lees, which contains yeast sediment) has some amount of B vitamins as well ?

    Thanks !
    Fleur de Lys

  126. ReneeAnn says

    The Jarrow Methyl B12 appears to not be corn-free. :( I’ve learned the hard way that I need corn-free. And, I prefer to not have the sugar alcohols, either, since I don’t do well with them. I see that it is free of wheat, gluten, soybeans, dairy, egg, fish/shellfish, peanuts/tree nuts, which covers a bit more than I need, except for the corn issue.

    Any thoughts for someone needing corn-free?

    I bought B12 Infusion by Enzymatic Therapy, which is corn-free, but I have not tried it, yet. It contains a sugar alcohol, so I don’t want to try it until my stuffy head clears up.

    • says

      Can you handle a very small amount of lactose? Superior Source makes super tiny instant dissolving sublinguals that are methylcobalamin in a base of lactose and acacia gum (no sweeteners).

      Natural Factors methylcobalamin sublinguals are also corn/gluten/soy/starch free (lactose base/sweetener free)

      • ReneeAnn says

        It seems strange, but I cannot even handle a small bit of lactose. It gives me sinus problems, which I battle with constantly. And, I don’t do well with gums. I looked at the Natural Factors and it does have lactose. Thanks for the suggestions, though! :)

        • Tanya says

          Check out the B12 drops on holisticheal.com. They have methyl, hydroxy and adenosyl types of B12. (I know this is a bit late, but maybe you’re getting follow-up posts by email.)

  127. sarah says

    my rudimentary observations have shown me that vegan/vegetarian women who reproduce are ending up with babies who store extreme amounts of fat and end up on the autism spectrum. could this be due to B12 deficiency? this observation based on at least 10 different women in my community…

  128. Jenn C says

    Hi Chris,
    Being someone on SCD with gut issues and and a few gut-resections, I cannot take sublingual due to the illegal flavorings. I have recently tried a B12 patch – I’m not sure if these are bogus? if so, what would you recommend?

    thanks, Jenn

    • Chris Kresser says

      I can’t tell from the B12 patch website, but I recall they use cyanocobalamin, which is an inferior (inactive) form that must be converted to active forms in the body.

    • Lily says

      Jenn, I don’t know what you are restricted from using sublingually, but I have a bottle of Natural Factors B12 methylcobalamin sublingual 1000 mcg that has no flavors, colors, citric acid, artificial sweeteners, etc.

      The ingredients are:
      lactose (from milk)
      croscarmelose sodium
      magnesium stearate (vegetable grade)

      Note: I think that this brand might also have B12 sublinguals of the same dosages, 1000 and 5000 mcg, that DO have that extra stuff in them, so read the labels carefully if you are thinking of purchasing these.

      I am pleased with it so far, but it’s the only methylcobalamin I’ve ever used and I’ve only just begun to take it, so I have no basis for comparison. I have gotten the feeling from reading various discussions in various forums about B12 deficiency that the Natural Factors methylcobalamin is not very highly regarded (in terms of its perceived potency) by experienced users of B12 supplements (such as Freddd and folks who swear by his B12 replenishment protocol). But it seems to be doing something for me, and I try to avoid all the unnecessary flavors/colors/sweeteners that I can.

  129. Michelle says

    Hi, I am currently battling with my Dr for further b12 tests after my bloods came back normal. Many members of my family (ibs sufferers) receive the injection. I have recently realised that my symptoms, ie very listless, snappy, very sore lips, NO memory, tingling hands, are more than likely due to this deficiency. I shall probably direct my Dr to this article in the hope of moving things on a little quicker! I am in 38 yr old omnivor with serious cheese cravings if relevant!

    • Sandra Brigham says

      Why not just go ahead a get a sublingual methyl B12 bottle and see how you feel after 2-4 wks? My serum B12 was 90 (extreme fatigue, ataxia, neuropathy, etc.) and she only wanted to give me one injection. I had pretty severe neuropathy in the left leg and foot (and mildly in the left arm and hand) and when I went from taking nothing to taking the sublingal cyano B12, it got a bit better over a few months. Then I read Dr. Kresser’s original blog article and switched to methyl B12. Within weeks almost all my neuropathy was gone (except when I accidentally ate gluten it came back; or if I eat too high a carb load or too many nuts). Why wait for your doc to address it if you’re feeling crappy. It’s very hard to overdose.

      • Jessica says

        May I ask what does of sub-lingual would be advisable? – I`m considering it myself. I`ve had a cobalamanin injection but the effects seem to wear off fairly quickly.

    • Sarah says

      Serum B12 tests are USELESS! B12 is water-soluble, so it’s more accurate to test urine than blood. If you’re not excreting much, then it’s highly likely you’re deficient.

      The one caveat here is, of course, that you could be excreting too much due to malabsorption issues caused by IBD, or other gut disorders.

      • Maria says

        Does anyone know how long one would have to suffer from B-12 deficiency for it to be irreversible? I believe that my dad was B-12 deficient from anti-acid use for heartburn. As far as I know his B-12 levels were never checked.

    • Juli says

      My dr. had me abstain from Vit D and Cerefolin (oral b12) for 2 or 3 weeks prior to re-testing. Her reasoning was that if the body wasn’t properly absorbing and refilling the stores of B12, then the tests would likely to be more accurate. So perhaps skipping supplementation for a couple of weeks prior to retesting would be a better test?

    • Lesley says

      There are several labs that let you walk in without a dr.’s order and order your own blood tests. why wait for your dr. to come to his senses while your health deteriorates…check with your local lab.

  130. Stephanie Furr says

    Very interesting article. About 13 years ago I was originally diagnosed with a blood disorder that required a bone marrow transplant and i was getting blood transfusions bi-weekly. I then decided to seek a second opinion, the second oncologist diagnosed me with anemia and started me on B-12 injections and folio acid. Within a month, my counts were almost perfect. The doctor had no explanation of why I was anemic. To this day, I still take monthly B-12 injections and supplement with folate. It was all very scary. I am thinking of starting sublingual to avoid the shots and having to get a prescription. What’s your thoughts?

  131. says

    The last supplement you mention, TMG (trimethylglycine) – is that found naturally as part of the glycine component of bone broth and therefore less important for the bone broth addicts out here? Thanks!

    • Chris Kresser says

      Yes. Always best to get it from food when possible. But for therapeutic cases, some may need to supplement.

    • Maria says

      You can and should have adrenal function tested by a saliva sample (4 times spread out throughout the day from 1st rising to bedtime) to test your cortisol levels. Will probably need to go to nathropathic Dr. as regular Dr. won’t worry about poor adrenal function until they’re barely functioning at all. Adrenal burnout is common when there’s prolonged stress and if your adrenals are not functioning properly, then you most likely also have thyroid issues. If this is the case, its important to fix the adrenals so you can resolve the thyroid problem.

  132. SB says

    Hi Chris- I am interested to find out what you know about Vit B sensitivity and overdose. I have symptoms of Vit B deficiency most of the time but whenever I encounter large amounts of B from a multi-vitamin, vitamin water type source, or B Complex supplement, after one or two doses, I begin getting overdose symptoms (major fatigue). I am also very sensitive to the natural sweetener stevia (flu like symptoms, feels like body is shutting down). I have had my liver enzymes checked and they are functioning fine. I have always been very sensitive to pharmaceuticals also (half life lasts much longer for me). Background: I am a fairly fit female in my 30s- 5’5″, 118 lbs. My body type seems to be a little more naturally acidic and my LDL cholesterol level trends a bit higher. I would love to hear your thoughts…. Thanks!

    • Amber says

      Your reaction to B vitamins is so similar to mine. I’m convinced I’m deficient ( I have ongoing gut issues I’m working on, and I think it’s effected absorption), but even with a natural food based B vitamin I had extreme fatigue and flu symptoms, reacting even after a single dose. When I take the Vit B complex it feels like overdose and herxheimers reaction rather than an allergic reaction–but I can’t be sure? I tried sticking it out for a couple weeks and kept taking it, but finally gave up til I can understand this better. I would love to see Chris respond to this!

    • Lily says

      SB above and Amber below,

      What you mention sounds like what has recently happened to me.

      Before I had come across Chris’ 2 blog postings about B12 or the other specialist websites that go in-depth about B12 replenishment (and thus I didn’t yet know that there are several supplements that should be taken ALONG WITH full-strength methylcobalamin), I had been taking a 1000 mcg tablet of methylcobalamin daily for 2 weeks with no problem, and the first steps of healing were really seeming to take place (in terms of my particular deficiency symptoms), but then I suddenly had a “potassium crash” that put me out of commission for about 36 hours (constant heart palpitations, lasting muscular cramps in my back and neck, feeling totally drained).

      I tried to find out what was happening to me and discovered that this kind of crash was common with methylcobalamin (this potential potassium imbalance, called hypokalemia, is even mentioned on the Wikipedia page for B12 deficiency, which I had actually read before I started taking the B12 supplement, but I had just not paid enough attention to that part). I rested, ate as many foods as I could find in the house that are high in potassium, and stopped taking the B12 until I could obtain the other 3 supplements that are meant to balance everything out.

      • Mel says

        What were the other 3 supps that are meant to balance everything out? And did you eventually stop taking the b-12? Or did you find a supp that has other additives?

    • Rose says

      I just started taking metformin. I only took three 500mg pills for 3 days along with dr. recommended b-complex and fish oil. I have been having a horrible reaction since. My body is so itchy from the inside out. From my head to my stomach and sides. My legs and arms itch so bad as well. Could this reaction be caused from the b vitamins?

      • Sarah says

        WHY ON *EARTH* ARE YOU BLAMING THE B12, AND *NOT* the metformin…?!

        Why are you even TAKING metformin…?! Why are you not taking control of your diet, instead of shoving Big Pharma’s poisons down your throat…?! That’s what I did – dump the poison and eat a LCHF – preferably Palaeo – diet. That’s what I did; not only did I lose my diabetes, I lost weight, too, 23 stone (322lb) to be exact.

        The itching is known as ‘pruritus’ and is a side-effect of the poison, NOT the B12.

        Other side-effects include: – anorexia (that’s the proper name for ‘loss of appetite’, it has NOTHING to do with the eating disorder, which should be referred to as ‘anorexia nervosa’), nausea, vomiting, diarrhoea, abdominal pain, taste disturbance, lactic acidosis, decreased B12 absorption, erythema (skin reddening), pruritus (itchiness), and urticaria (hives/nettle rash). Hepatitis has also been reported (list taken from the latest edition of the British National Formulary).

        Frankly, with a list of side-effects like that, I’d not want it within 100 miles of me – that’s why I changed my diet instead – but if you’re happy poisoning yourself, go right ahead…

        I believe that most disease is a response to an incorrect diet (somebody said she had coeliac disease, that’s the very one I use to illustrate my point; if wheat was something we were supposed to be ingesting, then why would ANYONE react to gluten…? I’d extend that to ALL grains).

        Obesity is a reaction to eating an incorrect diet, I’d term it a food intolerance. Eat to your genetic blueprint and you’ll not get fat and, if you ARE fat, eating to your genetic blueprint will make you not fat.

        Wasn’t it Hippocrates who said “All disease begins in the gut”…? That’s what he meant – an incorrect diet causes disease. I’d alter that to read “all disease begins – AND ENDS – in the gut” because the correct diet can heal.

        So step away from the metformin, and go and read Chris’s excellent articles on Palaeo for diabetes. Diet will RID you of your diabetes, Big Pharma’s toxins will not – DON’T CONTROL, CURE…

  133. Harlow says

    Hi Chris,

    I know that energy shots, like 5-hr energy and others, are not Paleo but they have been the one vice I can’t seem to shake. They contain a similar amount of caffeine as a large cup of coffee and contain mega-doses of B vitamins (B6, B12, B3, B9). I was just curious on what your thoughts were for these types of drinks from a health perspective for someone in maintenance mode (not trying to lose weight).

    Any input would be greatly appreciated.

    • Chris Kresser says

      You might not like my answer. The vitamins in these products are usually the lowest possible quality. Caffeine is individual; if you have adrenal/brain issues, it’s not a good idea. If not, there’s nothing wrong with it.

      • Sarah says


        You’re forgetting about the correlation between caffeine and Mg depletion. I’ve been taking high doses of caffeine for years, and am now suffering from osteomalacia (despite taking 15,000IU D3 for years). Without Mg, your body can’t utilise D.

    • Steve says

      Mega doses? There are hardly any B-vitamins in those things at all.. 30mg of Niacin (B3), that’s nothing. 40mg of B6, that’s nothing. 400mcg of Folic Acid (B9), that’s nothing. Perhaps the biggest joke of them all.. 500mcg of B12 (the worst form of b12 too).. 500mcg of b12 is a joke.

    • Chris Kresser says

      Pernicious anemia is another disease that causes B12 deficiency. But many docs now believe that high-dose, sublingual methyl B12 is equivalent or superior to injections in these cases.

      • Kristin says

        I have pernicious anemia, and have been injecting myself for the past four years. As I am only 35 and was told that I will have to do monthly injections for the rest of my life, sublingual b12 sounds like a much better way to go!

        How can the high-dose, sublingual b12 be absorbed by my body if I don’t have the intrinsic factor? Is the b12 absorbed into the bloodstream in the mouth somehow?

        Thanks for your time!

        • Chris Kresser says

          Sublingual preparations bypass the stomach so wouldn’t be absorbed via the digestive pathway that requires intrinsic factor. You’ll have to ask your doctor whether sublingual B12 can substitute for injections, but many physicians I work with use it for pernicious anemia cases (and I have also had good success with it).

          • Peter-NZ says

            A fixed proportion (1.2%) of ingested B12 is always absorbed by passive diffusion which doesn’t rely on IF. This is insignificant at doses obtained from food but highly significant in case of high dose supplements. I take one 5000 mcg sublingual methylcobalamine lozenge per week which should give me about 60 mcg of B12 per week.

          • Crissy Sirianni says

            Hi Chris,
            Do you recommend an iron supplement with b12 shots or sublinguals? My ferritin is very low at a 5. I’m on my 7th weekly shot of cyanocobalamin and was taking methyl sublingual pills daily and my symptoms just got worse. No one seems to talk about symptoms getting worse or a good treatment plan for b12 deficiency. I’m confused about that. Potassium levels can fall, b12 needs a sufficient amount of folate and iron if you are deficient. All these factors play a role in feeling better. It’s more than just a sublingual pill for some and you just feel better. Do you have any thoughts on how you treat your patients if they are deficient in b12 and anemic? And may have possible gallbladder issues.

      • Holly says

        I have celiacs and have been told that b12 is a common dificiency as well, i see no mention if celiacs herein?

        • Sarah says


          There’s a VERY simple cure for coeliac disease – simply STOP EATING GRAINS! Coeliac disease is the reason I always cite when people argue that grains are necessary for health – if we could assimilate nutrition from them, then coeliac disease wouldn’t exist! Grains are Neolithic and our bodies simply haven’t had the time to adapt. Grains are deleterious to health whether you’re coeliac or not: – they cause obesity (so do starches too by the way), obesity-related diseases, they’re immunosuppressant, they contain anti-nutrients (enzymes which prevent the assimilation of other nutrients) – they really are empty calories.

          I’ve been eating low-carb/high-fat palaeo for around 6 years (I did it because, at the time, I had a LOT of weight to lose (I was 30 stone (420lb) and type 2 diabetic). Lost 22.5st (315lb) in around 2 years. Now 7.5st (105) and a size 4/6 (0/2).

          You don’t need grains! Wheat gluten is one of those anti-nutrients which prevents the uptake of B12.

          • Liz says

            Hi Sarah,
            I have not been diagnosed w/celiac disease but recently found that although I have B12 in my system, I am deficient in B12 and folic acid in my red blood cells. I am now on 2x/week injections (just did my 3rd injection yesterday, haven’t seen much change yet in energy level, brain fog, cramping in hands, tingling in hands, feet, etc. BUT I am hoping and praying for the best!). When I had my blood drawn, along w/the deficiencies, I was found to have slightly high cholesterol. I have been advised by my doctor to omit grains, primarily gluten, as well as corn and dairy. I am wondering what your thoughts are on the Paleo diet b/c of high cholesterol, esp since you have been doing it for quite some time now.

            Honestly, I am at the end of my rope w/my health (or lack thereof). I have 3 small boys, I have no energy, my fuse is very short, I continue to gain weight, I don’t have energy to exercise except for sporadically…Anyone reading this who can provide me w/specific details on what you feel I should be eating, I greatly appreciate your input! ESPECIALLY when it is scientifically proven or tried and true through multiple experiences of pp w/B12 deficiency!

            • Inge says

              Hello, I just read your comment and was wondering how you know that you have a B12 deficiency in your red blood cells?

              • Jackie says

                I have two copies of the MTHFR c677t gene mutation and am benefiting greatly from a supplement called Homocysteine Supreme. In 6 weeks, my homocysteine level dropped from 14 to 10.

      • Kathy says


        Last week I was diagnosed with hemochromatosis and severe vitamin b defincecy. Today, I received my second weekly b12 injection and am starting to feel like the brain fog is starting to thin a bit.

        Is it common to be low in b and high in iron?



        • Lesley says

          Please see my comment to Liz above your post and consider getting tested for MTHFR mutation, it is relatively common approximately 45%+ of the population has it.

  134. says

    It’s interesting that vegetarians and vegans (like you, I used to follow these diets myself) think that they’re lowering their risks of heart disease when their deficiencies are actually elevating these risks. It’s surprising (or not surprising?) that in spite of the number of studies that demonstrate the devastating results of a B12 deficient diet, you rarely read or hear about it.

    Do you think that taking a sublingual methylcobalamin supplement is as effective as regularly consuming animal products (all other things being equal, like absorption)? I haven’t found any clear information on this issue.

    • Chris Kresser says

      Liz: I’m not sure who you’re addressing here? I am not a vegetarian now, though I was for a short time. At the time, I was experimenting with it for both ethical and health reasons, but I wasn’t doing it to lower my risk for heart disease.

      Sublingual methyl B12 may be equivalent in terms of B12 absorption, but of course it doesn’t have the many other benefits of consuming animal products.

      • says

        Sorry, Chris! I know you’re not a vegetarian today. I should have been more clear: one of the main reasons for following a plant-based diet is for health reasons, when actually there are risks due to deficiencies. We rarely see this issue discussed. Thanks!

        • Sarah says

          I’ve never been vegan/vegetarian, because I believe that veganism/fruitarianism are forms of ED; you’re cutting out whole food groups which are ESSENTIAL for optimum health and eating primarily Neolithic foods from which we can derive little – if any – nutrition.

          I used to follow – before I was banned – a FB group called ‘Veganism is the Future’ and some of the ‘facts’ they came up with (e.g. were YOU aware that cucumber was 40% protein? No, neither was I! Must be hiding in all that water… Does that mean water’s a good source then…?).

          What made me want to erupt was when the owner posted a pic of her DOG; the poor mutt looked emaciated (unsurprisingly) had a massive lump on the top of his head, and a nasty, raw, red wound under his left eye. I cannot ABIDE hypocrisy; they bang on about animal cruelty – then they get carnivorous pets and STARVE them! She claimed he was 16, but that long on a diet of plants…?! I cried! The comments sickened me – so many people calling him a “healthy dog” because he had a piece of broccoli in his mouth (obviously something wrong with their eyes)!

          According to his owner, dogs don’t need meat at all, they only need the nutrients FOUND in meat which, apparently, they can assimilate perfectly well from plants (so, by her logic, it’d be perfectly okay to feed a rabbit steak. I blame the lack of B12, cholesterol and fat!).

          So, as my parting shot, I posted a pic of a family of wolves (ironically her favourite animal) having lunch. She banned me for that. Guess it’s too much to be reminded that dogs are wolves…

          I’d like to make 2 comments about the post: –

          1. Whilst iron IS found in plants, non-heme iron is very poorly absorbed, when compared to heme. Also, green leafy veg, oft-touted to be the best source of non-heme iron, is actually no source at all, as it contains the anti-nutrient oxalate which completely prevents the iron being assimilated. Not only that, but it’ll prevent the assimilation of any iron contained in anything with which it’s eaten (so that braised calves’ liver in watercress sauce with a side of kale probably isn’t the best idea…).

          2. Vegans – and veggies to a lesser extent – are very likely to be lacking in vitamin D. Yes, it’s true it’s synthesised from the sun, but cholesterol is required in order to synthesise it – it’s chemical name IS colcalciferol after all – and anyone on a strict vegan diet is VERY unlikely to have much of that.

          I know you recommend Jarrow, but I’ve never found they do much for me at all – if anything, I feel MORE fatigued after taking them – even the 5mg. I’ve switched to NOW and they’re FAR better – AND the lozenges are about a quarter the size! YMMV, of course…

          • Anna says

            wow, okay then. Because you know, all Vegans think that Carnivorous animals should eat plants. -_- I have a cat and i feed him meat. Im Vegan. My cat is not. Im skeptical of plant based diets for Carnivores because Ive heard horror stories. But ive also heard horror stories of humans who were not doing the Vegan diet correctly (b12 supplements being part of that) and getting sick or dieing because they seemed to think that being Vegan meant eating only salad or something. As an aside, perhaps the wounds on the dogs face came from it running into something or some other accidental injury. And as long as the animal was healthy, happy, and had no sicknesses, then its fine. Its not animal abuse, although personally i would give the dog a chance to eat meat and see which one it likes best. i have a cat that, when given the chance, is all over a salad.

            • Anna says

              Although after doing a lot of research, i am considering making my cat vegan. He’s an excellent mouser, hes constantly catching and eating things that are natural for a cat to eat (as opposed to cows, pigs, turkeys etc, things cats would never eat in the wild) and none of that meat is diseased and over-processed and diluted with grains and fillers. He is catching it the way predators are meant to catch things. I think he would be fine on a plant-based diet, if done CORRECTLY. Just something i thought of after that comment that made me sound like im anti-vegan pets. Im not.

              • Angela says

                I am by no means bashing vegetarianism or veganism for humans, but please please do not consider a vegan diet for your cat. Cats are obligate carnivores and cannot survive on a diet that does not contain meat. Interestingly, there is one type of raw cat food on the market that is ground mice. Kind of odd and gross to think about…but much more natural than turkey, beef, etc., I will admit. :)

              • Lesley says

                Cats are true carnivores, they don’t need grains or starches. If they are eating their natural diet as a wild feline (mountain lion, cougar, bobcat, etc.) or feral feline they would be eating their prey, e.g.: mice, rabbits gophers, prairie dogs, voles, deer, chickens, etc. In doing so they would be eating MEAT and only the vegetables in the digestive tract of their prey. Please don’t try to turn your carnivorous cat into a vegan.

                • Sasha says

                  I have recently switched my puppy to a vegan diet – and it has seemed to get his epilepsy under control! So please don’t assume that all vegans who feed their dog vegan diets are doing it for their beliefs – I still feed my other dog meat – however something about the meat was contributing to his seizures (vet thinks it was antibiotics in meat).

          • Dr.Dawn says

            Thank-you for taking the time to write this post. I have also posted on various vegan FB pages and websites… apparently, their unhealthy diet affects their reasoning skills. The scariest is when they put a baby or child on their diet. There’s a reason that the North Koreans are, on average, about 3 inches shorter than South Koreans. None of the 5 longest-living groups of people was vegetarian or vegan.

  135. John Ritterbush says

    Ooops. Looks like the links to the suggested supplements are broken. Looks like you got a little CSS in your HREF, if you know what I mean…

  136. says

    My wife and I were vegetarian for 15 years. She has MS (20yrs). We changed our diet to Paleo Feb ’12 as we didn’t feel either of us was getting the proper nutrition. I must say I feel much better/energized, and my wife’s state is much improved. However, we have implemented other therapies so it’s hard to say the exact effect our diet had to do with her improvement.

  137. Angela says

    Hi Chris – The links in your last paragraph are all dead. Thanks for the great post on B12. I was recently told that I had a B12 deficiency and I would like to purchase the Jarrow Methyl B12. I’ll wait for your links to work so that you get your commission for my purchase.

    • Chris Kresser says

      Some physicians feel they are superior in the case of neurological problems, but other experts believe the opposite: that high-dose sublingual is a better choice in all cases.

      • Judy says


        When my B12 level was at a severe low 41, I had to do a series of injections to get my level up.
        Unfortunately, permanent nerve damage was done cuz no one found it early enough. But a few years ago I researched other ways if taking prescribed B12 in a nasal spray called Nascobal and taken as directed my level has been stable around 700. So no more injections, it costs more but if you have insurance it helps a little and to me is well worth it. I thought I’d share this with you.

      • Jacqueline says

        What do you consider high dose? And can you include a regimen, for example, should I amp up the dosage for a few months and then titrate back down to 1-3 mg per day?

      • Sarah says

        I understand that there is also a nasal spray (this is by prescription) and there are B12 patches (not by prescription).

  138. Lindsay says

    Hi Chris,

    Interesting stuff. Have you found that people with a functional deficiency sometimes show elevations in serum B12?


      • Lindsay says

        Great! I look forward to your take. I have developed numbness and tingling in the past 6 months. My reg doctor tested my B12 which came in at 1257 pg/ml, but I wasn’t supplementing. She just brushed it off. It took a functional doc to connect the dots between my gastro issues and my likely malabsorption of B12 despite my high intake of animal foods. I was a vegetarian/vegan for 13 years.. that should have clued my reg doc in! Ah well. I have been supplementing 1000 mcg liquid methyl for 6 days. There is a noticeable difference, but I still have tingling. Hopefully the damage isn’t permanent. Fingers crossed!

        • Sheila says

          I have the same exact issue I went to over 20 Doctors and no one would help me.I started researching high b12 and found this site im so thankful for it! Im not crazy…I did find a Functional Dr he seems to understand the problems im having but has not treated me with B12 yet.Today I am very sick brain fog, shortness of breath, Tingling hands and feet, anxiety, depression, ect. I feel im at the end of my rope I found out 5 years ago I had high b12 and every time its tested its the same in the rage of 1200’s I just need help :(

          • Denise says

            Sheila, I am no Doctor but this sounds like you have Hypothyroid and adrenal fatigue – worth checking out !

            • Sheila says

              I jus saw your response,ive been checked 10 times in the last year and a half for thyroid issues the blood work is always normal T3 T4 antibodies negative the did discover a nodule on each side but my endo said they were non toxic.As far as adrenal gland I took a saliva test it was just slightly off.No one knows whats wrong but since going gluten free I feel 50% better im not healed but I pray im getting there.Thank you for your response.

              • Doodie says

                Sheila, you need to have a free T3 & T4 test done & also find a doc who takes your symptoms into diagnosing, like temp. 3 times a day under tonge with an old fashioned thermometer, not a digital one. Just diagnosing only with blood work is not good practicing on doc’s part. If your temp. Is below 98.6 most of the day, you have thyroid issues.
                Check out Dr David Brownstein’s website, he’s phenomenal concerning thyroid & Iodoral supplements that I’ve been on for 2 yrs., it will help your thyroid & other things & you won’t have to get on thyroid meds. In fact lots of people are able to get off their thyroid meds due to Iodoral. I buy it off internet, amazon, Optimox, lucky Vitamins sells it & not expensive.

                • sue says

                  hi i went on to look for Iodoral and it comes up on vitamin sites as iodine is this what it is ? thanks in advance .

                • Alysa Fleisher says

                  Yes Iodoral is an iodine supplement. This is NOT the solution for everyone. This is only if you are iodine deficient. Most people in a non third world country consume plenty of iodine through processsed foods. I on the other hand have a problem with absorption of iodine, B-12 and a host of other vitamins & minerals but supplementation doesn’t change what the tests show. I even don’t absorb my thyroid meds correctly so I have lots of T4 but its not free and I don’t convert it to T3 either. So far my doctors are at a loss for what is causing my issues; but they still continue to work on it. I wish you luck.

            • says

              I have had progress perferral neurothapy for 10 it started when i 55. I was a tema kick boxer, dancer and extremely active over the last 15 years I have Hyparthroidism Hyparcalcuim attacking me for 5 years. It it has progressed to past my ankles and I get looked ankles, I have start compounds, and compound pills. That have hight b 12 my circulation shows like a cyle very hot weather and very cold get me. I feel helpless. I wear certain shoes, and I am not diebtic. I just had triple by pass, So now protien is important, and be can be found in certain beans. I eat lot of fish, (can not have what is on Chris’s list of which I love) I nee to find some to help me slow this going up my legs….As I will be in a wheel chair. My mouth feels like it burns, teeth are sensitive all throught the mouth, no root problems, but lot of years that many teeth are caped or permanent bridge. I don’t know if neurothapy can go into gums, but it feels like my teeth are hurting (not a tooth ache, and can not eat probably. That’s whe I tried this site.

              I am a young 68….My brain is very clear. Plus my energy is good, it’s the neuropthy that kills my days, I have to put my feet up, but a compound cream on for this so called pain I have it all electricity going from my toes to almost my chins. I still keep exercising for my heart (as will for the rest of life) but I can’t even be consistent. Which is not a good thing. Well thanks for this time and I hope my mouth is not showing thinning of bones of which comes fro Thyroid (high calcium counts) that distroy so many things bone, diggestion, memory I feel like I am in a catch 22. There are cycles but the are not half has long as they were.

              Help if you know a doctor, or research showing how we get it better to conduct our lifes.
              Much appreciation for reading
              Mj in Charleston SC

          • utkarsh says

          • Natasha P says

            Sheila, we are like one in the same. After going through all the testing with no explanation for all of the symptoms you described, I researched and had myself tested for MTHFR. I was positive for homozygous C677t and have since then researched more of my genetic mutations finding that I can’t absorb Folic Acid and recycle my B12. Tests always show no deficiencies for B vitamins but my body can’t methylate and put them into use properly. Your story is so similar to so many that I have read about. Have yourself tested. You can even order a kit online through 23 andme.com or ancestry.com. They are about $99 and can be kept private. There is an option where you can access your raw genetic data. There are other sites online that will translate the results to you like Nutrahacker.com, geneticgenie.com, and livewello.com.

      • Amanda says

        What is your normal course of action when you see elevated serum B12 and a functional deficiency? I know that you said you were reserving judgment on Spectracell, but my daughter showed a functional deficiency with their micronutrient analysis and an elevated serum B12 with a standard blood test. Observationally, my daughter had the tingling in her extremities and mood changes that could be explained by B12 deficiency. I have just started here on 1000 ug/day sublingual B12. What is your rationale for these seemingly opposing lab results?

      • Judy says

        Hi Chris

        Very interesting article, I only wish I knew about this 8 years ago. My B12 level was 41. I’m now disabled and unable to work. I do the best I can around the house but its hard and tiring.
        I’d like to hear from you about this.

        • Deborah says


          you should go onto http://www.phoenixrising.me or http://www.howirecovered.com. there is a man on phoenix rising called freddd who was disabled due to b12 deficiency and has managed to recover something like 95% of his health through using methyl B12. it is NOT too late!!!

          i have been doing his protocol for the last 3 months or so myself and am seeing improvments in my health too, actually saw improvments immediately (i am just badly deficient, but was presenting with neurological symptoms like brain fog, depression and numbness)

          dont give up, you may be able to do some thing to help fix it. it won’t be easy but it is possible.

          i hope that you feel better


    • Honora says

      I wonder if the high serum B12 reflects a high analog level and that would be why the individual is deficient. I guess if a true ‘active B12′ level was done, the person would be found to be deficient in the genuine B12. Interested in this especially as one of my colleague’s husband has a very high B12 level (around 1200 pmol/L, I think).

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