Vitamin B12 Deficiency: What It Is, Symptoms & Treatment | Chris Kresser

A Silent Epidemic with Serious Consequences—What You Need to Know about B12 Deficiency

by Chris Kresser

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This tired man rubbing his eyes may be experiencing B12 deficiency.
Fatigue is a common symptom of B12 deficiency.

What do all of these chronic diseases have in common?

  • Alzheimer’s, dementia, cognitive decline, and memory loss (collectively referred to as “aging”)
  • Multiple sclerosis (MS) and other neurological disorders
  • Mental illnesses like depression, anxiety, bipolar disorder, and psychosis
  • Cardiovascular disease
  • Learning or developmental disorders in kids
  • Autism spectrum disorder
  • Autoimmune disease and immune dysregulation
  • Cancer
  • Male and female infertility

Answer: They can all mimic the signs and symptoms of a vitamin B12 deficiency.

An Invisible Epidemic

B12 deficiency isn’t a bizarre, mysterious disease. It’s written about in every medical textbook, and its causes and effects are well-established in the scientific literature.

However, the condition is far more common than most healthcare practitioners and the general public realize. Data from a Tufts University study suggests that 40 percent of people between the ages of 26 and 83 have plasma B12 levels in the low normal range—a range at which many experience neurological symptoms. Nine percent had an outright nutrient deficiency, and 16 percent exhibited “near deficiency.” Most surprising to the researchers was the fact that low B12 levels were as common in younger people as they were in the elderly. (1)

That said, this type of deficiency has been estimated to affect about 40 percent of people over 60 years of age. It’s entirely possible that at least some of the symptoms we attribute to “normal” aging—such as memory loss, cognitive decline, and decreased mobility—are at least in part caused by a deficiency.

Why Is It Underdiagnosed?

B12 deficiency is significantly underdiagnosed for two reasons. First, it’s not routinely tested by most physicians. Second, the low end of the laboratory reference range is too low.

This is why most studies underestimate true levels of deficiency. Many deficient people have so-called “normal” levels of B12.

Yet, it is well-established in the scientific literature that people with B12 levels between 200 pg/mL and 350 pg/mL—levels considered “normal” in the U.S.—have clear vitamin deficiency symptoms. (2) Experts who specialize in the diagnosis and treatment of a deficiency, like Sally Pacholok, R.N., and Jeffrey Stuart, D.O., suggest treating all patients that are symptomatic and have B12 levels less than 450 pg/mL. (3) They also recommend treating patients who show normal B12 levels but also have elevated urinary methylmalonic acid (MMA), homocysteine, or holotranscobalamin, which are other markers of a deficiency in vitamin B12.

B12 deficiency can mimic the signs of Alzheimer’s, dementia, multiple sclerosis, and several mental illnesses. Find out what this vitamin does and learn how to treat a deficiency.

In Japan and Europe, the lower limit for B12 is between 500 and 550 pg/mL. Those levels are associated with psychological and behavioral symptoms, such as:

  • Cognitive decline
  • Dementia
  • Memory loss (4)

Some experts have speculated that the acceptance of higher levels as normal in Japan and the willingness to treat levels considered “normal” in the U.S. explain the low rates of Alzheimer’s and dementia in that country.

What Is Vitamin B12 and Why Do You Need It?

Vitamin B12 works together with folate in the synthesis of DNA and red blood cells. It’s also involved in the production of the myelin sheath around the nerves and the conduction of nerve impulses. You can think of the brain and the nervous system as a big tangle of wires. Myelin is the insulation that protects those wires and helps them to conduct messages.

Severe B12 deficiency in conditions like pernicious anemia (an autoimmune condition where the body destroys intrinsic factor, a protein necessary for the absorption of the vitamin) used to be fatal until scientists figured out death could be prevented by feeding patients raw liver, which contains high amounts of B12. But anemia is the final stage of a deficiency. Long before anemia sets in, deficient patients will experience several other problems, including fatigue, lethargy, weakness, memory loss, and neurological and psychiatric problems.

The Stages of a Deficiency

B12 deficiency occurs in four stages, beginning with declining blood levels of the vitamin (stage I), progressing to low cellular concentrations of the vitamin (stage II), an increased blood level of homocysteine and a decreased rate of DNA synthesis (stage III), and finally, macrocytic anemia (stage IV). (5)

Common B12 Deficiency Symptoms

The signs can look like the symptoms of several other serious disorders, and the neurological effects of low B12 can be especially troubling.

Here are some of the most common vitamin B12 deficiency symptoms:

  • Tingling or numbness in the hands and feet
  • Brain fog, confusion, and memory problems
  • Depression
  • Premature aging
  • Cognitive decline
  • Anemia
  • Weakness
  • Fatigue
  • Reduced appetite and weight loss
  • Constipation
  • Trouble balancing (6)

Children can also show symptoms, including developmental issues and learning disabilities, if their B12 levels are too low.

Why Is It So Common?

The absorption of B12 is complex and involves several steps—any of which can go wrong. Any of the following can cause B12 malabsorption:

  • Intestinal dysbiosis
  • Leaky gut and gut inflammation
  • Atrophic gastritis or hypochlorhydria, or low stomach acid
  • Pernicious anemia
  • Medications, especially proton pump inhibitors (PPIs) and other acid-suppressing drugs
  • Alcohol
  • Exposure to nitrous oxide, during either surgery or recreational use

This explains why a deficiency can occur even in people eating large amounts of B12-containing animal products. In fact, many of my patients that are B12 deficient are following a Paleo diet where they eat meat two or three times daily.

Who Is at Risk for a Deficiency?

In general, the following groups are at greatest risk for a deficiency:

  • Vegetarians and vegans
  • People aged 60 or over
  • People who regularly use PPIs or acid-suppressing drugs
  • People on diabetes drugs like metformin
  • People with Crohn’s disease, ulcerative colitis, celiac, or IBS
  • Women with a history of infertility and miscarriage

Note to Vegetarians and Vegans: B12 Is Found Only in Animal Products

You cannot get B12 from plant-based sources. This vitamin is only found in animal products. That’s why vegetarians and vegans need to know the signs of deficiency—and the steps necessary to fix the problem.

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.

A common myth among vegetarians and vegans is that it’s possible to get B12 from plant sources like:

  • Seaweed
  • Fermented soy
  • Spirulina
  • Brewers yeast

However, plant foods said to contain B12 actually contain B12 analogs called cobamides that block the intake of and increase the need for true B12. (7) That explains why studies consistently demonstrate that up to 50 percent of long-term vegetarians and 80 percent of vegans are deficient in B12. (8, 9)

The Impact of a Deficiency on Children

The effects of B12 deficiency on kids are especially alarming. Studies have shown that kids raised until age six on a vegan diet are still B12 deficient even years after they start eating at least some animal products. In one study, the researchers found an association between a child’s B12 status and their performance on testing measuring:

  • Spatial ability
  • Fluid intelligence
  • Short-term memory

Researchers found that formerly vegan children scored lower than their omnivorous counterparts in each area. (10)

The deficit in fluid intelligence is particularly troubling, the researchers said, because this area impacts a child’s ability to reason, work through complex problems, learn, and engage in abstract thinking. Defects in any of these areas could have long-term consequences for kids.

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 absolutely 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 with B12.

This is especially important for vegetarian or vegan children or pregnant women, whose need for B12 is even greater. If you’re not willing to take a dietary supplement, it may be time to think twice about your vegetarian or vegan diet.

How to Treat a Deficiency

One of the greatest tragedies of the B12 epidemic is that diagnosis and treatment are relatively easy and cheap—especially when compared to the treatment patients will need if they’re in a late stage of deficiency. A B12 test can be performed by any laboratory, and it should be covered by insurance. If you don’t have insurance, you can order it yourself from a lab like DirectLabs.com.

As always, adequate treatment depends on the underlying mechanism causing the problem. People with pernicious anemia or inflammatory gut disorders like Crohn’s disease are likely to have impaired absorption for their entire lives and will likely require B12 injections indefinitely. This may also be true for those with a severe deficiency that’s causing neurological symptoms.

Some recent studies have suggested that high-dose oral or nasal administration may be as effective as injections for those with B12 malabsorption problems. (11) However, most B12 experts still recommend injections for people with pernicious anemia and an advanced deficiency involving neurological symptoms.

Try Supplementing

Cyanocobalamin is the most frequently used form of B12 supplementation in the U.S. But recent evidence suggests that hydroxocobalamin (frequently used in Europe) is superior to cyanocobalamin, and methylcobalamin may be superior to both—especially for neurological disease.

Japanese studies indicate that methylcobalamin is even more effective in treating neurological symptoms and that it may be better absorbed because it bypasses several potential problems in the B12 absorption cycle. (12, 13) On top of that, methylcobalamin provides the body with methyl groups that play a role in various biological processes important to overall health.

Change Your Diet

Nourishing your body through whole food is the best way to get the vitamins and nutrients you need. If you’re low on B12, try eating some vitamin-rich foods like:

Eating other kinds of seafood, like octopus, fish eggs, lobster, and crab, can also help you attain normal B12 levels. If you’re seafood-averse, you can also get this vitamin from:

  • Lamb
  • Beef
  • Eggs
  • Cheese

It’s important to note, though, that the amount of B12 in these foods is nowhere near as high as the levels in shellfish and organ meats.

What to Do if You’re Experiencing Vitamin B12 Deficiency Symptoms

If you suspect you have a deficiency, the first step is to get tested. You need an accurate baseline to work from.

If you are B12 deficient, the next step is to identify the mechanism causing the deficiency. You’ll probably need help from a medical practitioner for this part. Once the mechanism is identified, the appropriate form (injection, oral, sublingual, or nasal) of supplementation, the dose, and the length of treatment can be selected.

So, next time you or someone you know is “having a senior moment,” remember: It might not be “just aging.” It could be B12 deficiency.

Now, I’d like you to share your experience. Have you experienced any of the symptoms associated with low B12? How do you make sure you get enough of this vitamin to stay healthy? Tell me in the comments below.

1,962 Comments

Join the conversation

  1. I discovered that i am b12 deficient in 2014. Along with that i had low ferritin. As doctors prescribed taking b12 shots, i started taking them but i was looking for the reason behind this deficiency. My brother has wheat allergy(celiac) so one of the doctors asked me also to get tested.But it was negative. My digestion was never good. I had bloating, gas, vomitings, headaches and hair fall. Recently i thought to quit milk and results are amazing, no more gas bloating and headaches. Its been only a month.
    I am confused whether i am having wheat allergy or not(I am on a strict non celiac diet from the past 1 year), coz i have read that for some people it doesn’t show in their test and celiac runs in the family(my brother has it).
    second question is can lactose intolerance leads to low b12 and ferritin? Please somebody help.

  2. I’m wondering if some of the people here who still have really low levels of B12 despite injections, etc. might not have liver problems. Maybe too, some kind of cancer? Cancer can cause all kinds of weird symptoms even when it’s still small. I don’t know how you can test for it, though, if you don’t know what type you are looking for. You can have tests for liver function done, though, along with a sonogram. You might want to have your kidneys checked while you are at it.

    • I had B12 and D deficiency but after some time on supliments, my blood work is normal with the exception of a low reading of 11 for Gamma Glutamyl Transferase ( range is 14 – 62 U/L) . My Glomerular Filtration rate was 79 (An eGFR from 60 – 89 ml/min/1.73 m2 is consistent with mildly decreasing kidney function) . I could never find anything out about the low Gamma Glutamyl Transferase and all my doctors tells me is that low is better than high without providing any details.

  3. My my what a big long thread of comments

    Hello Chris

    At the top of the page you forgot to mention *Cholesterol (&or Statin provoked medical conditions).

    A few years ago I am thinking “I am doing everything right but can not get my cholesterol test right”
    The best I could get out of the cholesterol group was the triglyceride down to almost half 1.1 mmol/L where the pass is <2 by saying a absolutely NO to any food I thought had “toxic” sugar in it.
    The breakthrough came when I was reading “Your Blood Never Lies” it was suggested by the author James LaValle RPh, CCN to look at Homocysteine. So next time I had a cholesterol test I added it in as a extra private test. After the results came I made a visit to my naturopath (who in fact teaches doctors how to read blood test) the Homocysteine was over the limit at 19.8 when the limit was 5-15umol/L.
    It was suggested next time I get a blood test to go for a vitamin B-12 test, I wish now I had of gone back just to test B-12 because 3 months later the Homocysteine had gone worse from 19.8 to 22.1 umol/L and Vitamin-B12 was 161 pmol/L the high end of the borderline 110-170 the pass is 170-600 pmol/L. But despite that the over all cholesterol had dropped a bit better and closer to the border line fail apart from the HDL cholesterol, so I think my diet & lifestyle must be right for good cholesterol apart from the B-12 deficiencies.

    My naturopath added it is the B12 deficiencies that makes the homocysteine to go up, then that in turn makes your cholesterol go up, and added high homocysteine does far more damage than high cholesterol. I wish I could pass this information onto James LaValle as it is missing from his book and could be worthwhile added in to his next edition, if it turns out my naturopath is correct, the next cholesterol test is lookinggood. On page 208 there is a list of food for Iron, Folate & Vitamin-B12, as I have a high end pass for iron I can see some foods on the list I have in my diet, the same for folate (I get a mid range pass) but can not see many foods I get out for the B12 apart from the odd smoked salmon I get from time to time. Interesting enough in the book it says for high than normal calcium could be “Control your homocysteine ……” & you guessed I have high end normal for calcium on a OligoScan mineral hand scan use internet to learn more on OligoScan reports.

  4. Hi, i’m 32 years old and already 6 years suffering from depression. i’m getting treat by antidepressant drugs “ssri” everyday and b12 injection one a month.
    every half a year my b12 decreased to 180 and i’m feeling extreme depression. so, usually i’m doing series of injection (about 6 at 2 weeks) and i’m feeling excellent, and so forth.

    month ago i did the same series of injections and felt better. but this time only after a month its came back: sadness, depression, no energy. i did blood test and its shows 180 again . how could it be after a series of 6 injection month ago.

    something got wrong, what/how its could be? my blood not absorbing b12? or maybe ther are any influence/ correlation between the antidepressant to b12? im feeling very bad, what can i do?

    i would appreciate any kind of advise and treatment.
    thank you 🙂

    • Luba, what form was being injected? I read that the most common type used for injecting was cyanobalamin, the least useful type to our bodies. Maybe you’re not converting it to the active form.

      I’ve just been reading a ton of useful information here:
      http://www.b12-vitamin.com/

  5. what type of test will show me my TRUE/REAL b12 status…

    there are many tests recommended like total B12, active B12, homocysteine, serum folate, RBC folate etc…?

  6. Eleven years ago I found out I have a severe B12 defiency. My level was 41. I’ve been using the B12 oils (methylcibalamin) you can order online for years now. My level has been very good. But my symptoms really haven’t gotten better. My gait is still bad, short-term memory problems, weak very stiff muscles and more. My doctor doesn’t really know what else to do. I use a cane for short distances and a rollater for long distance. I’ve learned to live with this but it does get me down a lot.

    • Hi, Judy – perhaps you try and read about the Wahl’s Protocol, you can find an article even here, in the section Immunity & Autoimmune Disease. It looks from your description like you may benefit from her diet, even if you are not diagnosed with any of autoimmune problems. Her diet increases energy levels providing all essential nutrients needed to produce more energy on a cellular level. She has her website and there are books / ebooks on Amazon as well if you are interested to become familiar with her works.

  7. I went to the doctor for really bad signs of demetia or alzhiemers, muscle wasting, weakness,depression,hand and head tremors and back pain. They sent me to mental health and the did blood work. I was sent to a neurologist and she did tests and prescribed me B12 1000 mcg. My level is 350. She never told me I was B12 deficient or anything. I am also taking vitamin D3 5000 once a week. I was doing really good and I didn’t take any B12 for about 8 days and everything came back like everything !! I started my pills again and ordered the methyl type online. I’ve been in the dark all this time. Thank God for articles like this. I super depressed right now. They are starting neurological behavior testing.

      • Instead of doing this outside the box testing why not just supplement along with increasing meats (i.e. B12 rich foods) if symptoms are present.

        The B12 lozenges are super cheap. it can’t hurt even if you don’t need it. End of discussion.

    • “vitamin D3 5000 once a week” This is way, way low. Recently revised recommended daily levels are for 8,000 iu a day of D3. Take with preformed Vitamin A as well, to keep them in balance, or simply eat a lot of liver or other organ meats.

      • I was found to be B12 deficient with many of the symptoms discussed on this form. I was also found to be vitamin D deficient. Not sure if the 2 are some how related. I started taking over the counter b12 suplements and a lot of the symptoms got considerably better but not all. When I finally started taking vitamin D suplements, that is when the symptoms finally disapeared. Testing for Vitamin D is expensive and so a lot of doctors do not want to do it and in Canada some government plans do not cover the testing unless you have a defficiency. Not that my doctor put me on 1000 per day which proved to not be enouogh and I am now on 3000 per day which is proving to be adequate in my case. The specialist sent me for the initial D testing ( it was covered if a specialist sent you but not if a GP sent you) and now that I have been shown deficient, I am covered regardless of who sends me.
        Good Luck

        • Note – I was also taking magnesium and I am no longer taking Magnesium as my levels are fine – A lot of the food I eat is high in magnesium and that seems to be adequate to maintain my levels.

  8. B12 and magnesium . Long story short – last summer, I was having issues such as tingling arms and tingling legs, off balance and head pressure. blood tests showed that my B12 was low (77) and so I went on over the counter B12 (1200mcg) . This over a period of months cleared up all the symptoms . In mid February of this year, my blood tests showed a high B12 level (703 – range is from 138 – 652) . Everything else showed within limits . When i went to a neurologist (mid April) , he told me to start taking Magnesium (250 mg per day) he ordered additional blood work which showed a b12 level of 546 (I had backed off on the b12 supplements due to high reading), a low vitamin D level of 47 (75 – 250) is the range, a low reading of 11 for Gamma Glutamyl Transferase ( range is 14 – 62 U/L) . My Glomerular Filtration rate was 79 (An eGFR from 60 – 89 ml/min/1.73 m2 is consistent with mildly decreasing kidney function) .

    Everything else tested was in range .

    The last blood test taken in early may (ordered by my family doctor showed a b12 reading of 676 (Hi), a magnesium level of 0.98 (range is 0.7 – 1.0 mmol/L) and confirmed the other readings from the previous blood work.
    In early May I stared taking a vitamin D supplement (1000 IU 25mcg) as well as the B12, Complex B100, a one a day vitamin and 250 mg Magnesium I was already taking.

    shortly after starting to take the magnesium Symptoms (tingling in arms and legs and head , off balance feeling, pleasure in ears and head) came back.

    Has anyone had any issues, similar issues as a result of to much/ hi b12 / magnesium or a combination of? Also, I could find little on what Low Gamma Glutamyl Transferase means as most problems are related to high readings and so any insight on that or anything else I have written above would be appreciated.

    Thanks Marpy

    • note that after the last blood test showing high b12, I continued taking my B12 as the doctor did not say to stop and as such, my level could have gone considerably higher. I stopped taking the B12 yesterday after reading that to much could cause side effects – some similar to what I am experiencing. My B100 Complex contain 100 mcg of B12 which I figure should with my change in diet to eat more foods fortified with and containing B12 maintain a healthy level for me.

    • It isn’t possible to have B12 levels that are too high. B12 overdose is impossible, as the vitamin is water soluble, and any excess is excreted-this has been proven in studies where patients were given extremely high doses of b12 over a period of time with absolutely no ill effects. Of the B vitamins, only B6 is toxic in high doses.

      It should be noted that a high reading of serum B12 does not mean you’re “cured”. If you are still having deficiency symptoms, you still have a deficiency. The only way to know how much b12 in your blood is actually being used by your body is an Active B12 test, which are hard to get and usually expensive.

      If you’re supplementing with B12, you need to supplement with Magnesium and Folate or Folic Acid (whichever works better for you) as B12 methylization requires Folate and depletes magnesium, as well as potassium, which should be supplemented by high potassium foods only if your levels are low. Too much potassium is dangerous and can cause heart issues and stroke. You should have your ferritin (blood iron stores levels) tested, as people with b12 def often have low iron as well.

      • Hi Tracy – Thanks for the reply. My Magnesium and potassium levels were checked and were on the high side of acceptable limits. My B6 was not checked. What I am taking B6 wise is a multivitamin (2.5 mg) and B100 complex (100 mg) . My understanding based on an internet check is that the maximum recommended daily intake for B6 is 100 mg and the daily recommended intake is less than 2 mg. As such between diet and supplements, I am somewhat over the maximum daily and way over the recommended daily . As such I will stop taking the B100 complex. This is considering that my levels for everything vitamin wise checked during my last blood test was good with the exception of Vitamin D. I will stay on the vitamin D and the one a day vitamin and see what that does.
        Thanks for the information – Marpy

        • I have be off the B100 complex (which contains 100 mg of B6) for 3 days now and my symptoms have improved considerably. I was wandering if anyone has any idea of how long it takes for the B6 in a persons system to get down to normal levels? The tingling feeling in arms and legs is much better but still experiencing off balance ringing ears and light headednes although not as bad. Thank you

          • usually the protocol with b6 is 4 months on 2 months off. I would have your b6 levels checked. If you feel you need to supplement other b vitamins, find a b that contains no b6

            • Thanks Tracy. I was only on the B100 and magnesium for 3 weeks and began feeling the symptoms (off balance, tingly arms and legs, shaky feeling, ear pressure) within days of starting to take them. These symptoms seemed to be slowly improving even while I was taking the Magnesium and B6 but really got much better within days of when I stopped taking magnesium and B6. I have for 15 years or more some twitching in my right eye lid and left cheek that comes ant goes as well. This as well got worse and then got better when I went off the B6 and Magnesium. I was wandering if B6 in the amount I was taking over a short period of time can cause this ?
              Next time I am in to see the doctor, I will ask for a B6 test as it has never been tested for in the blood tests that they sent me for to date.

              Thanks Marpy

                • Thanks Tracey – I will visit the FB site. Base don last blood test, my B12 levels were up around 700. My symptoms were almost completely gone till I started taking the Magnesium and The B100’S . I was never tested for B6 but will ask the next time I am at the doctors (3 weeks). I had read that some people will have symptoms when they go on B100’S as their body has to adjust. Lots of information out there but some is conflicting and so I am trying to get a better understanding. Especially with respect to the B6.
                  Thank You
                  Marpy

    • Yes, organ meats can easily supply B12, and other nutrients like choline; nutrients that are hard to find in other natural foods. Liver and other organ meats are not liked or consumed by many westerners. And anyway, doctors still are recommending limiting the consumption of cholesterol. So nutrients like B12 and choline are not consumed in adequate amounts via natural foods. Doctors and other health professionals also recommend limiting sun exposure and to always wear sunscreen, which helps contribute to vitamin D deficiency. Are doctors working with us or against us. Doctors need to get their acts together. Bad communication, and bad information plagues us.

      • Doctors are still following the outdated and debunked Ancil Keys study about fats and cholesterol. And, let’s not forget, statins (cholesterol meds) are one of the most prescribed (and most profitable) medications. Doctors are barely trained in nutrition and vitamin deficiency, and are still trained in theories that are no longer useful. It is up to us to take charge of our own health.

        • Both myself and my father have suffered from fatty liver at one time. In doing about 10 minutes of research on the internet, I found that low choline can be a cause of this condition. I started eating more eggs, and also (on days I didn’t eat eggs) started using a supplement. Fatty liver gone; liver enzymes back to normal. My doctor knew nothing about this. Doctors really don’t know that much about nutrition (as you said).

          • We are the ones that are responsible for our health… no else… just us.

            People are so busy trying to get their kids into the best schools… so busy being good consumers… so busy that they don’t bother with health related learnings… until it’s too late. Actually, even then, most people don’t bother to learn… they’d rather pay for advice and pay for some pills. After all, that’s what good consumers do.

            A return to true ancestral living is the paradigm shift.

  9. A couple of years ago I had the same thing. Numbs legs all the way to my hips. I also had a very red throat that didn’t allow me to eat hardly anything. Finally I was diagnosed with a B12 deficiency, my level was 75. Not good. Hospitalized for 4 days, received shots every day, then weekly and then monthly. I finally gained all feeling back in my feet and legs. Took many months, so hang in there! I have since been diagonosed with pernicious anemia and am not able to absorb B12 through food, just shots. So now I give myself shots every 2 weeks. Monthly was not enough for me. B12 does not stay in my system very long. I’m told everyone is different. So just listen to your body and don’t let anyone tell you that your amounts of B12 are high enough. Also read the book “Could it be B12”? I found it has some good information even though I knew I had a deficiency.

    • So crazy how doctors always have people shoot once a month or once per three months even. This is never enough. If you check blood test on the internet for example for b6 or so, they say that if you take b12 injections, one should stop for a week before the test cause it may influence the test. This kind of tells me that the b12 shorts stay in your body for about a week. I inject myself every week instead of what my doctor told me to do it once per 3 months. I found out about my b12 absorbtion problem because I had many, many miscarriages for years. My serum b12 level was 241 and in the Netherlands this means there is no problem but some grey area. I insisted on injections and right after my first shot when I got pregnant again (I got pregnant every month) IT STAYD and I did not have a miscarriage. I also noted my egg came on day 12 when on b12 injections while before it was always day 4 to 9. Now, if I stop injecting for just 1 month, I have my ovulation on day 4, for me this is prove that I need to shoot more frequently so I shoot every week. I also noticed I got back to being tired and depressed again, so I will now take folate with it, I think this should help. I already take magnesium so my hopes are on folate 5-MTHF (don’t take folic acid cause that chemical fake stuff that can cause problems).

  10. About a year ago I was finally tested and found to be B12 deficient. 138 My numbness was all the way up my legs past my hips. I was afraid I was headed for a wheelchair. I started taking the shots and my numbers responded quickly. I still have numbness in my feet. I am wondering if this will ever go away. Is there a therapy or exercise? another vitamin supplement?

    • I have read about b12 patches you can get online. That’s my next try. I’m getting injections every week for the last 6 months or better and I’ve barely creeped up to 300. I still feel like garbage but better than before.

  11. Hi
    I was diagnosed with b12 deficiency 2 years back(with level = 130 )and was treated the normal way (B12 shots every day for a week, then weekly and then monthly for 3-4 months). I got my levels checked, they were around 700. Almost all of my symptoms were gone. But now since 3-4 months, I started feeling the symptoms were coming back. I started taking b12 shots 1000 mcg monthly and I feel better. Anyone out there felt the same? or anyone taking B12 shots since many years?

    • Try jarrow b12 lozenges from Amazon. I heard some users getting limits of 1999 because she took too much, like 3 a day which is way to high. Recommended dose is 1 per day you can chew. I took one today for the first time and man I felt great. Pure clarity and calm.

    • have you been tested for Intrinsic Factor antibodies? It sounds like you might have an absorption problem which could indicate Pernicious Anemia. Have you had other blood tests? MMA and Homocysteine? Elevated levels are also indicative of PA. It would explain your recurrence of symptoms and the lowering of your b12.

    • B patches have been proven ineffective because the B molecules are too large to be absorbed trans dermally.
      Nice idea but does not work.

  12. My daughter was diagnose with a seveve vitamin B12 deficiency . She has had one B12 injection.She has a severe case of under the skin swelling, itching and peeling on her face, ears and moving onto her neck. Her face is red with leather like spots. Could this be as a result of her b12 deficiency? She has had it for 6 months and doctors say it is eycema and will have to live with it. The only treatment of the symptoms that helps is acupuncture but they isn’t treating the cause! Her skin is back to normal after a treatment but lasts only about 3 days. What are your thoughts and/or suggestions? HELP!!!

  13. Dr. Kresser, I didn’t see MTHFR mutations as a cause of B12 deficiency. Is MTHFR homo- or hetero- zygous mutations not a cause of a deficiency?

    • I had been having trouble for 3 years with tingling in hands and feet. Thought it was topamax i was taking for migraines. Past year i almost fall asleep while driving heart palaptations in last 2 months had gotten so bad I thought i was having a heart attack. Leg cramps were waking me up at night, started drinking coconut water with potassium which helped a lot with those. But chalked it all up to thyroid. Went to dr and she tested my b12…im at 182 deficient. I have started shots. 2 shots, one a week so far. 2 more in 2 weeks. Then once a month for 3 months. My heart palaptations have stopped….one now and then. Leg cramps so so. Tingling is a little less. I now itch like crazy no hives. And mild headaches are slowing that were getting bad. I hope this works.

      • Leg cramping is due to Magnesium deficiency most likely since calcium is a muscle control tractor(and we get more then enough in our diets) magnesium is a muscle relaxer! I love it and take powder form of magnesium twice a day in warm water (the blue bottle brand Calm found at whole foods! Cheers!

  14. Hi. I read some of the comments and replies on this conversation. I am too a B12 deficiency for almost 2 years now. At first, I tried the over the counter tablet but it made me so constipated!. Then, I talked to my doctor that I don’t want over the counter B12 vitamin and she suggested the B12 injections. Right now, I have been doing the injections. When my lab work results came out, it was low 152 and I have 4x a month B12 injection until it went down to once a month injections. From time to time, it will be almost normal B12 range then it will go down again. But one thing that really help me is eating liver! My mom will cook for liver and I will eat it for a week then my symptoms will be gone..

    • Azolla an aquatic fern and algae spirulina and chlorella are the best and naturally source of Vitamin B12. The Good thing about this is that they are tasteless so you can add flavour to it. Try these, after that, your Vitamin B12 deficiency is controlled.

        • I wish folk would get it right:

          Many people say that the only foods which contain vitamin B12 are animal-derived foods. This is untrue. No foods naturally contain vitamin B12 – neither animal or plant foods. Vitamin B12 is a microbe – a bacteria – it is produced by microorganisms

        • That part sounds like a joke. According to this article, logically all vegetarians should have neuropathy and severe symptoms. My whole family and forefathers have been vegetarians for thousands of years, one of most healthy and happy people on earth. i personally don’t recommend being veg or no veg, but this article is surely misleading.

          • Vitamin B12 CANNOT BE FOUND IN PLANTS. Period. The only edible source of vitamin B12 is through meat. I’m sorry if this violates your sensibilities, but numerous scientific studies have proven that cobalamin is only found in meat and the B12 found i plants and micro organisms is an analog. Until the analog is consumed and digested and absorbed into the animal’s body, it is useless to humans. If you object to eating meat, use a b12 supplement.

      • There are no natural plant substitutes for a true B12 plants carry a sub catagory which is of no use to human use and can actually make uptake of genuine B 12 less effective Many vegetarians / vegans are under this false illusion and are making themselves sick.

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