Vitamin D: More Is Not Always Better | Chris Kresser
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Vitamin D: More Is Not Better


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Have you been told you need more vitamin D? Healthcare practitioners are increasingly aware of the risks of low vitamin D levels, but many are not aware that high levels of vitamin D can have toxic effects. Read on to learn the risks of over-supplementation, what factors determine your optimal vitamin D level, and the many reasons to get sunlight exposure beyond just vitamin D.

optimal vitamin d levels
Testing your vitamin D levels is essential to prevent vitamin D toxicity.

Vitamin D is critical for health. Virtually every cell in the body has a vitamin D receptor, which, when bound to vitamin D, can influence the expression of more than 200 genes (1, 2). Vitamin D promotes calcium absorption in the intestine and maintains calcium and phosphate levels in the blood, protecting against osteoporosis, rickets, and bone fracture (3, 4). It also regulates immune function, cell growth, and neuromuscular function (5, 6).

With the many roles that vitamin D plays in the body, deficiency of this fat-soluble vitamin is a real cause for concern. Vitamin D deficiency has been found to increase the risk of heart attack, cancer, diabetes, asthma, and autoimmune disease (7, 8, 9, 10, 11, 12). Our modern indoor lifestyle limits our sun exposure, and we can only get a small amount of vitamin D from diet (13). According to the lower boundary of the U.S. lab range of 30 ng/mL, as many as 70 percent of Americans are considered deficient (14, 15).

It’s great that awareness about vitamin D deficiency is increasing, with more doctors than ever testing vitamin D levels. However, like many nutrients, vitamin D follows a U-shaped curve, meaning that both low levels and very high levels are associated with negative health outcomes (16). Unfortunately, few practitioners are aware of the dangers of vitamin D toxicity, and many just test serum vitamin D once and recommend a daily 5,000 or 10,000 IU supplement to their patients.

In this article, I’ll discuss the risks of over-supplementation, why you should get most of your vitamin D from sunlight, and the reasoning behind my current approach to vitamin D.

Risks of Excess Vitamin D Supplementation

Vitamin D status is measured by 25(OH)D in blood. We’ll dive further into vitamin D metabolism later, but for now, just understand that this is the precursor to active vitamin D and is generally considered the most accurate single marker to assess vitamin D status. The U.S. laboratory reference range for adequate 25(OH)D is 30 to 74 ng/mL, while the Vitamin D Council suggests a higher range of 40 to 80 ng/mL, with a target of 50 ng/mL (17).

But a large body of evidence in the medical literature strongly suggests that optimal vitamin D levels might be lower than these figures. There is little to no evidence showing benefit to 25(OH)D levels above 50 ng/mL, and increasing evidence to suggest that levels of this magnitude may cause harm. Consequences of vitamin D toxicity include heart attack, stroke, kidney stones, headache, nausea, vomiting, diarrhea, anorexia, weight loss, and low bone density (18).

Furthermore, in most studies, taking vitamin D supplements does not decrease risk of death, cardiovascular disease, or other conditions. Based on an exhaustive review of over 1,000 studies in 2011, the Institute of Medicine recommends a much more conservative range of 20 to 50 ng/mL (19).

Some research on Israeli lifeguards suggests that, contrary to popular belief, vitamin D toxicity from sunlight alone (in the absence of supplementation) is possible (20). That said, it is  much more difficult to achieve toxic levels through sun exposure alone. Sunlight is the optimal source of vitamin D, and has numerous  benefits above and beyond improving vitamin D status.

Can your vitamin D levels be too high? I think so.

Beyond Vitamin D: The Many Benefits of Sunlight

Vitamin D is really just the tip of the iceberg when it comes to the benefits of sunlight. A recent 20-year study following 29,518 subjects found that those individuals avoiding sun exposure were twice as likely to die from all causes (21). While this study did not assess vitamin D levels, findings from other epidemiological studies suggest that this cannot be accounted for by the increase in vitamin D production alone.

Indeed, humans make several important peptide and hormone “photoproducts” when our skin is exposed to the UVB wavelength of sunlight (22). These include:

  • β-Endorphin: a natural opiate that induces relaxation and increases pain tolerance (23, 24)
  • Calcitonin Gene-Related Peptide: a vasodilator that protects against hypertension, vascular inflammation, and oxidative stress (25)
  • Substance P: a neuropeptide that promotes blood flow and regulates the immune system in response to acute stressors (26)
  • Adrenocorticotropic Hormone: a polypeptide hormone that controls cortisol release by the adrenal glands, thus regulating the immune system and inflammation (27)
  • Melanocyte-Stimulating Hormone: a polypeptide hormone that reduces appetite, increases libido, and is also responsible for increased skin pigmentation (27)

Exposure to the UVA wavelength of sunlight has also been shown to have benefits, including increasing the release of nitric oxide from storage (28). Nitric oxide is a potent cellular signaling molecule that dilates the blood vessels and thus reduces blood pressure (29).

In addition to the production of photoproducts and release of nitric oxide, sunlight also entrains circadian rhythms. Exposure to bright light during the day activates neurons in the suprachiasmatic nucleus of the hypothalamus, which sends signals to the pineal gland that regulate melatonin production. Disruption of circadian rhythm has been associated with mood disorders, cognitive deficits, and metabolic syndrome (30, 31).

Vitamin D Optimal Levels

Optimal Vitamin D Range Depends on Many Factors

So how much do you need? At the first annual IHH-UCSF Paleo Symposium in San Francisco this year, nutritional biochemist Dr. Chris Masterjohn summarized evidence suggesting that optimal vitamin D levels may vary from population to population, despite the fact that there is currently only one reference range used for all patients.

Ethnicity is one major consideration. For example, black people have lower 25(OH)D than white people in the U.S., yet they typically have much higher bone mineral density. Furthermore, non-Caucasians have lower 25(OH)D levels than Caucasians, even at their ancestral latitudes (32). From these and other studies, it has been suggested that people with non-white ancestry may be adapted to a lower optimal 25(OH)D level than people with white ancestry.

Another factor that influences toxicity is nutritional status. The fat-soluble vitamins A, D, and K work synergistically, and adequate vitamin A and K may protect against toxic effects of excess vitamin D (33). Sufficient levels of potassium and magnesium have also been suggested to protect against vitamin D toxicity (34). Unfortunately, most people have nutrient deficiencies in these micronutrients in the developed world, making them more susceptible to vitamin D toxicity.

What about optimal vitamin D range from an evolutionary perspective? A study on traditionally living hunter–gatherer populations in East Africa found that the Masai and Hadzabe tribes had average 25(OH)D concentrations of 48 ng/mL and 44 ng/mL, respectively (35). These indigenous populations get a great deal of sun exposure but also have very high intakes of vitamins A and K, suggesting that these levels are probably towards the higher end of the optimal range for most people in the modern world.

Using Parathyroid Hormone Levels to Individualize Vitamin D Testing

As we saw in the last section, 25(OH)D lab ranges should vary by population, genetics, and nutritional status. In the absence of specific ranges, we need other biological markers that can help to clarify vitamin D status. To find these biological markers, we need to look at how vitamin D is metabolized.

When UVB contacts the skin epidermis, vitamin D is produced from 7-dehydrocholesterol. This vitamin D then travels in the blood to the liver, where it undergoes primary hydroxylation (the addition of a hydroxyl group, consisting of one oxygen and one hydrogen atom) on the 25th carbon atom. The result is 25(OH)D, which is the metabolite most widely used to assess nutritional vitamin D status. This compound circulates in the blood until it undergoes secondary hydroxylation on the first carbon atom in the kidney, resulting in 1,25(OH)2D, the active form of vitamin D (36).

You might be wondering: why don’t we test the active form? While certainly informative, the amount of active vitamin D is not directly reflective of nutritional vitamin D status because the secondary hydroxylation step is tightly regulated by parathyroid hormone (37). When the parathyroid glands sense a drop of blood calcium levels, they secrete parathyroid hormone (PTH). PTH stimulates the formation of active vitamin D, which increases calcium absorption in the small intestine and calcium release from bone in an attempt to restore normal blood calcium levels (38).

High PTH levels can therefore lead to high 1,25(OH)2D, low bone mineral density, increased risk of fractures, and osteoporosis (39).

With a basic understanding of this pathway, we can use PTH, calcium, and active vitamin D3 as markers to give us a more complete picture of someone’s vitamin D status. In his presentation at IHH-UCSF, Dr. Masterjohn suggested that serum PTH levels above 30 pg/mL may be indicative of biological vitamin D deficiency when 25(OH)D levels are borderline low. Conversely, if 25(OH)D levels are borderline low or even slightly below the laboratory reference range (e.g., 25 to 30 ng/mL), but PTH is less than 30 pg/mL, it is unlikely that the patient is vitamin D deficient, and supplementation is not warranted.

Instead of focusing on the 25(OH)D level itself, what we really want to achieve is maximum suppression of PTH levels for optimal calcium homeostasis and bone health. Beyond this level, more vitamin D is not necessarily better.


Based on my assessment of the literature and my own clinical experience, I believe the functional range for 25(OH)D is around 35 to 60 ng/mL. However, I can’t stress enough that there is significant variation among populations. For those with non-white ancestry, the optimal range may be a bit lower. For those with autoimmune disease, the optimal range might be a bit higher (45 to 60 ng/mL) to maximize the immune-regulating benefits of vitamin D. Here are a few recommendations for optimizing your vitamin D level.

  1. Don’t supplement blindly.
    If your 25(OH)D level is:
  • less than 20 ng/mL: you likely need some combination of UV exposure, cod liver oil, and a vitamin D supplement
  • 20 to 35 ng/mL: get your PTH tested. If PTH is adequately suppressed (less than 30 pg/mL), supplementing is probably unnecessary.
  • 35 to 50 ng/mL: continue your current diet and lifestyle for maintaining adequate vitamin D
  • greater than 50 ng/mL: try reducing your vitamin D supplements, and make sure you are getting adequate amounts of the other fat-soluble vitamins to protect against toxicity
  1. Get retested!
    Check your levels after three to four months to see if you have achieved or maintained adequate levels of vitamin D. If not, adjust your diet, lifestyle, or supplements accordingly and check again in another three to four months.
  1. Get sunlight or UV exposure as your primary form of vitamin D.
    Reap the many benefits of sunlight beyond just subcutaneous production of vitamin D, and reduce your chance of achieving toxic levels. Spend about 15 to 30 minutes, or about half the time it takes your skin to turn pink, in direct sunlight. Sunscreens not only block production of vitamin D, but also all of the other beneficial photoproducts produced in the skin in response to UVB.
  2. Mind your micronutrients to protect against toxicity.
    Try cod liver oil as a good source of vitamins A and D and high-vitamin butter oil or pastured butter and ghee for vitamin K. Sweet potatoes, bananas, plantains, and avocados all contain significant amounts of potassium. Consider supplementing with magnesium as it is very difficult to get adequate amounts of this micronutrient from food due to soil depletion.

Research Spotlight: Health Coaching and Nutrient Deficiencies

Web-Based Nutrition Intervention Improves Nutrient Biomarkers

In-person coaching approaches have demonstrated efficacy for improving patient health and motivation for change in previous clinical trials. However, one-on-one coaching sessions are financially unrealistic for many people. Until recently, it was uncertain whether these interventions could be administered on a large scale and still produce health benefits. A 2018 study assessed the effects of a web-based intervention on health biomarkers, including several markers for common nutrient deficiencies.

Study Summary

  • A longitudinal analysis of blood biomarker data was conducted on samples from 1,032 “apparently healthy” individuals using an automated, web-based nutrition and lifestyle program called InsideTracker.
  • Blood samples were taken at baseline and post-intervention to identify biomarker changes and to correlate these changes to nutrition and lifestyle intervention choices.
  • The duration of the intervention varied widely, with participants engaging in the program for anywhere from three months to 60 months. The intervention recommendations generated for each individual by the web-based program were synthesized from a broad scientific literature base of interventions associated with changes in biomarker levels. For example, an individual with high cholesterol may have been advised to increase oatmeal consumption.
  • Throughout the study, biomarkers showed a trend toward normalcy in participants who were out of range at baseline. Participants with baseline deficiencies in vitamin D and low levels of ferritin, a biomarker for iron status, experienced significant improvements in these markers post-intervention, indicating a normalization of vitamin D and iron deficiencies.

Key Findings

This research indicates that an online health coaching platform is useful for promoting diet and lifestyle behaviors that restore healthy vitamin D and iron status in deficient individuals. These findings suggest that personalized nutrition can be made more accessible through web-based health coaching programs that serve a large group of people.

While this study used an automated system to deliver appropriate interventions to subjects based on their respective biomarkers, a health coach could interact with clients on a more supportive, empowering level, along with the invaluable “human aspect” that is absent in fully automated coaching programs.

A weakness of this study was that it did not require retesting of biomarkers at specific intervals. Very long intervals between baseline and post-baseline testing may have confounded some of the improvements in biomarkers observed with the web-based program. Online, large-scale health coaching programs should incorporate retesting at specified intervals to optimize the efficacy of the coaching intervention. 

Reference:Longitudinal analysis of biomarker data from a personalized nutrition platform in healthy subjects”

The primary job of a health coach is not to act as a nutrition and lifestyle expert. However, having insight into core Functional Health topics—like nutrient density and nutrient status—can help coaches better integrate into a collaborative healthcare environment and relate to what their clients are experiencing. That’s why the ADAPT Health Coach Training Program includes comprehensive, evidence-backed information on Functional Health and ancestral lifestyle and nutrition. Is a future as a Functional Health coach right for you?


Join the conversation

  1. I would love to get tested more often but I’m not working right now so I’m winging it.

    How do I get more calcium absorption? I get baaaaad leg cramps. Years ago I began to supplement with 400-600 mg of magnesium to stop it. It did go down, but when I worked a 12 hour shift compounded by not enough sleep (nightshift) I would still be plagued with horrible leg cramps.
    Later I increased my vitamin D as I read that would help. It did, a little. Still occasionally got leg cramps especially on the murderous night shift. (I can handle the 12 hour shifts better if they are daytime. I can’t sleep more than 4 hours in the daytime).
    More recently, I was looking up insomnia once again and ran across Joel Wallach’s Wallach encyclopedia, and I read about Calcium! Ahah! For years I have deliberately avoided calcium supplements because I thought I got enough in drinking milk ( always been a milk drinker- back in the 60’s and 70’s I have come to believe those dairies still let their cows out on grass at least some of the time as I had strong teeth (until age 32) and didn’t have to supplement with vitamin K2, now it is essential, as I only get green growth for my animals (goats-milk, chickens;eggs, rabbits- meat, and my rabbits have fat- I believe in feeding them, and its yellow, chickens too) for a limited part of the year as our season is very short and I haven’t yet gotten my ideal irrigation system set up.

    Back to my Calcium- so if you read the Wallach wisdom on calcium, there is a chart, and most supplements he says since they are rocks, (most common is limestone-calcium carbonate) we only absorb about : “First of all, there’s metallic minerals. These are things like oyster shell, egg shell, limestone, coral calcium, sea bed minerals, clays of various types, Tums is a popular one with doctors, lactates, gluconates, citrates, oxides, sulfates, carbonates. These are nothing but ground up rocks. Animals and human beings are only able to get 8 to 12% of these minerals. We are not designed to eat ground up rocks as a source of minerals. When you hit 40 or 50 years of age, have you ever wondered why people suddenly fall apart when they hit the big 50. People dread turning 50 for that reason. The back goes, their teeth get loose, whatever hair you’ve got left is gray, no interest in sex. You just kind of fall apart. That’s because your ability to absorb these elemental minerals drop precipitously to 3 – 5%.”

    So I started by taking about 6 of the cheap limestone calciums from Grocery outlet, and within 2 hours, my arthritis is much reduced. And I sleep better.

    But I know it’s not the best form, it turns out bone meal, surprise, surprise, is a more absorbed form. So I’m taking that- there was a scare on bone meal two decades ago but now there are cleaner sources, (if you do bone broths and I try my best, if it’s not your own home raised animals, how do you know how clean it is? Unless you have a cheap way to have everything tested. )

    But I am taking at least 3 heaping teaspoons of bone meal, daily, 10,000 IU of vitamin D (look up Sarfraz Zaidi’s The Power of Vitamin D, his clinical patients have taught him that the need for D averages about 10,000 IU per day, his practice is in Ventura , sunny S CA (I am at 40 latitude, I lose IVB rays about Sept through May), he found only ONE patient to have optimal D, she was a lifeguard, in a swimsuit 5 hours a day 5 days a week, so much for 15 minutes a day on the arms and legs.
    There is also sulfur needed to combine the D, see Stephanie Seneff’s great interview with Dr Mercola on that fascinating subject.
    There is also the Study published on the Weston Price website on true vitamin A and Vitamin D working as a team to remove risk of toxicity;
    So I’m on sulfur (MSM 1 gram a day), D(10,000 IU), K2 (60 mg , yes you read that right, no puny micrograms for me), magnesium (at least 1 gram or more a day), vitamin A (25,000 IU a day, I have high needs, I have to go optimal until I get results), natural B complex, C (12 grams a day), natural E 1000 IU, etc. ZInc/copper for bones too.

    I would love to reduce my doses and save money, but when I do I get leg cramps again. and the diarrhea comes back (note no diarrhea on high dose C). And various other problems get worse. Is there anything I’m missing that will boost calcium absorption? I am thinking I still may not be absorbing it.

    • Thank you. I’m
      Always grateful hearing the news from others. Vitamin D in particular has been of great interest as I live in a temperate rain forest. Yes, Seattle area and this year the dark of sky started earlier and is a thicker gray.
      It’s suggested now that the dark increases onset of Alzheimer’s.

      When I moved here decades ago I hung shop lights inside my window frames instinctively and put them in timers so yes, fool my brain into thinking it was lighter outside and longer. It’s dark here around 4 pm and timers would go off around 9 pm.

      What it did was desensitize me to the dark. It was only needed about 2 seasons, then it didn’t bother me again. But this year I notice a need for more light. Full spectrum bulbs are ideal I think.
      Concerning D, before al the new news in it, I became very low in mood for awhile a long while back. I actually had great difficulty getting out of bed. Assuming depression I read everything I could find but nothing helped doctors put me in anti depressants and they were a nightmare for me. I gave up after awhile. Then a doctor tested my D and said it was dangerously low but didn’t even suggest a dosage. I wasn’t sure what to take. I took the small dose suggested and it was no help.

      I kept searching for answers.
      But at times I felt pinned to the bed through my chest it seemed. It was so strange and yet I would drag myself around. I felt confused and my memory was not good.
      Soon news on D came out. I asked doctors for large dosages. It’s dufficult to get d back into a normal range.
      Doctors wouldn’t give me prescriptions but I was reading how people were getting prescription doses. High doses.
      Finally only a few years ago a doctor gave me higher doses for 4 days.
      Since then I started experimenting with higher doses. I like 10,000 a day. I can sure tell the difference. But I do wonder if I might hurt myself with this so I have been trying to take it 3,4 times a week.
      I’d like to take it daily so far as how it makes me feel.
      I also take omegas and a product with iodine. I eat a banana at night if I get cramps in my feet.
      I take a multi vitamin but I need minerals and from past history mezotrace is great. I have trouble breathing at times, middle of my back hurts and diaphragm tightens up.
      Taking 3 mezotrace tablets 3 times a day for 3 days knocks that right out.
      Of course I need to keep taking it but it’s hard to swallow those large pills 9 a day. I have a very small throat.
      There is a powder.
      Add to smoothie but haven’t seen it at stores in awhile.

      Btw a friend of mine elderly started losing her memory. I suspected vit d. I told the family. They did nothing.
      She was sent to a hospital to live.
      When she got there they tested her and said her memory loss was due to low D. It was not recoverable and they didn’t give her large doses. She died last spring. Her memory had shifted dramatically and quickly. That’s why I suspected it was low vitamin D.

      Today with the depressed climate of low income and threatened benefits etc its more important we heal ourselves with foods and supplements and light. But it’s harder to do so.
      And when folks are put into old folks homes they aren’t going to be naturally treated.
      I feel we need a cooperative to buy wholesale and get our needs met. And to help one another through these challenging oppressive times.
      Any ideas are appreciated.
      Be sure to share your information and help someone with supplementation if at all possible.
      Let’s all stay strong.

      I’m resending this with edits.
      Btw I had really difficult migraines and pain in upper torso. It was debilitating. I learned here that I have a problem with many foods. Including cheeses, anything fermented, so many foods that didn’t bother me everytime I ate them so couldn’t figure out. I’m histamine intolerant. It’s a hard road. I’d like to hear more in that and also I have an auto immune disorder that attacks my joints and organs.
      Many people have auto immune stuff.
      Please supple the best news in healing for these concerns. Thank you.

  2. thanks for the info chris. I have always had my doubts over whether vitamin D is good for the body or not? can anyone provide me with a few resources to read about it?

    • These numbers being put out are far too low to cause toxicity. You have to be in the 100,000’s of thousands to millions of IU’s to become toxic and for more than a week everyday at those levels.

      I have been taking 20-40,000 IU’s a day for a week and I feel better than I have in 15 years.
      And let me just interject; the week I started mass dosing vitamin D liquid form, I stopped an 8 year long pain killer addiction, which was destroying my testosterone. Low T was causing all kinds of phantom pains and fatigue, among other problems like muscles not healing properly when exercised etc..

      I’ve now been off pain killers for 3 weeks, and I don’t plan on going back to them because they cause more problems than they solve.
      I should also mention I’m a red head who doesn’t go in the sun very much.. So maybe that is a reason why I can tolerate these higher doses of Hormone D lol.. I been working out for the last 2 weeks and honestly, this vit d feels like a steroid more than anything.

      And, I would just like to point out, vitamin D is the best anti-depressant on the market.. With no side effects unless you reach toxic levels, which I don’t believe are reported in this article correctly.

  3. Hi Chris! I am 31 year old female, 5’6, and 125 lbs. I have never had my PTH tested, but I do have low grade Hashimoto’s (inherited from my Dad). Thankfully, I am not yet hypothyroid. After testing my vit d a cpl years ago (it was 25) my Dr wanted to raise it and prescribed a short course of large dosage vit d (I think it was 40,000 iu daily for a cpl weeks). At that time my blood calcium was 9.5, which I believe is right in the middle of the ref range. After the short course, my blood calcium was the same and vit d was in the mid 40’s. Objective achieved. I then started a maintenance dose of 2000 iu daily. Next year my vit d was back down to 33 and my blood calcium was 9.7. After that I started taking higher doses of vit d (5000 iu daily) to get it back up in the 40’s and a year later I am now at my highest level of vit d at 45…but my blood calcium is now 10.3! My Dr isn’t concerned , but I am. I could tell something has been off bc I haven’t been feeling very energetic at all and kinda just overall unwell. Is it possible that all the vit d has given me a parathyroid issue? Another scenario I’ve thought of is maybe my lowish vit d was just where my body felt happiest, with my parathyroid managing the calcium and d balance in its way based on my own body chemistry. After all, I’m a pale face of northern European ancestry so I doubt my ppl were spending much time baking in the sun. Thanks!

    • When you take high doses of vitamin D you need to take magnesium because it gets depleted and vitamin K2 to ensure that the calcium goes to your bones, not your arteries. When it goes to your arteries your calcium levels come higher when you test your blood.

    • If your serum calcium levels stays at the level of 10.3 or higher, consider looking at PTH also. If your vitamin D levels without supplementation persist on being low (you’d need to stop again for a period as it’s a fat soluble and would take a while to drop), then consider any serum calcium above 10 with suspicion (although you’re still pretty young so a higher serum calcium is still possibly normal).
      Symptoms of generally unwell and lacking energy suggest need to check serum calcium more regularly and if above 10
      the possibility of a parathyroid benign tumor. No, vitamin D would not be known to cause a parathyroid problem, rather a tumor could be responsible for the low vitamin d ( if you weren’t supplementing (see

  4. Could it be that my levels of ~80 IU (could be more as I am about to be tested for a bunch of things) be the cause of my very recently diagnosed low bone density – osteopenia bordering osteoarthritis, following several stress fractures that I sustained while running? I’m asking because at 1st my levels were low and after I was put on 400 units, I raised my dose to 2000 – 5000 untis MCT based, depends on time of year. I will say briefly that I also have G6PD, anemia with high Ferritin levels and Hashimoto and had my gallbladder taken out. I objected to the surgery, until the pain won (I didn’t know about Paleo at the time). Sometime last year and after complaining about not feeling well and failed attempts to balance my thyroid, I was refereed to endocrinologist who at my own urging put me on combination therapy of T4 and T3 (Cynomel made by a French Co) which I am still straggling with. It was only than that I was warned that my level are considered high, while my GP who knew of the above for a long time, never said a word. Or could my deteriorating bone health has to do with a steroid inhaler (there’s data to support that) that I’ve been using for a while, due to esophagus issues; namely, elusive food allergy that couldn’t be detected so far, that at times causes my throat to clam shut and cause me to choke. I am taking 90 mcg of K7 and just order a new batch that I intend on taking twice a day (180 mcg), while stopping my D supplement (switching back to omega 3 from krill since my cod liver oil has 2,000 units of vitamin D). I also take Magnesium, zinc, selenium and astaxanthin; I tried N-A-C but I ended up with a rash on both sides of my neck. Chris, I would love to get your feedback and what are the chances of reversing my bone density. Assuming it nothing more serious.. I am about to be tested for other causes at the “cellular level”, such as bench Jones and many more…and yes it’s scary….Crowd sourcing input is welcomed as well 🙂

    * I’ve been reading you for a while and this is my 1st comment. Keep up the excellent work

    • Just to clarify, I should have wrote ~80 ng/ml and not IU. Also, my comment about my family physician not saying anything was concerning my Vitamin D levels… Again, I hope you’ll find the time to reply.

  5. I would love to have you comment on how much calcium we should get to balance the D/K/A/Mg recommended. If a person can’t eat dairy (or are eating paleo) and does not want to eat canned sardines every day, how many servings of green plants are needed to not get into trouble with bone loss? Do we need to account for oxalates preventing the calcium from being absorbed? Thank you!

  6. Here is the problem with Vitamin D in a nutshell.

    Vitamin D is what draws calcium into your blood serum. Unless that calcium gets processed, it will kill you over time with calcium deposits. This is the danger.

    The calcium-binding properties of osteocalcin require vitamin K, whereas the synthesis of osteocalcin itself requires vitamin D3.

    To play it safe, you should take both forms of K2 in the MK4 and MK7 forms since research has supported both.

    In Japan, they treat osteoporosis with 15 mg of MK4 3 X day. That’s 45 mg per day.

    You also need fat soluble A in at least a retinol palmitate form. There is debate on how much to take. I take about 3000 IU.

    If you are low on boron, your parathyroid gland can be dysfunctional. Your parathyroid has the most boron of any organ in your body. It also needs some Iodine also.

    Boron deficiency causes the parathyroids to become overactive, releasing too much parathyroid hormone which raises the blood level of calcium by releasing calcium from bones and teeth. This then leads to arthritis, osteoporosis and tooth decay. With advancing age, high blood levels of calcium lead to calcification of soft tissues causing muscle contractions and stiffness; calcification of endocrine glands, especially the pineal gland and the ovaries; arteriosclerosis; kidney stones and calcification of the kidneys, ultimately leading to kidney failure.

    I did cure my rheumatoid arthritis with 1/4 tsp of borax in lukewarm glass of water upon rising. It took 20 days before I started to fell the affect. I increase my boron with borax,

    You also need magnesium to balance the calcium.

    Manganese is important in bone building process.

    Bioavailable silica is also important. e.g. JarrowSil, BioSil. This is what actually creates bones that won’t fracture. It is responsible for laying the collagen matrix on the bone where the calcium gets deposited. It is a critical factor on whether you will have good bs bad quality bone. Without this, higher density bone is useless.

    If you are going to use calcium, use MCHA calcium.

    Focusing on D levels is losing sight of the bigger picture and putting you on the road to your obituary.

    You need to account for the entire process

  7. I have a quick question. I came across a radio show where a Dr.Wallach mentioned that cholecalciferol is found in rat poison and hence humans should avoid it at all costs. I wanted to get your input on it.

    • Yes, cholecalciferol can be used as rat poison. It is a question of dose. There are massive amounts in the grain-based rat poison which interfere with kidney function in the target pest. I have seen it stapled in bags on to trees in the New Zealand conservation estate.

      I delight in telling silly people who call warfarin rat poison that Vitamin D is also rat poison and as with warfarin, it is a question of dose. I’m sure if someone drank so much water as to lower their serum potassium and sodium, they would manage to kill themselves too e.g. people who take ectasy.

  8. 30/12/2016
    Hi everyone. Hope 2017 is good for you all. Now Re Vit D3.
    I’ve just read on here that some Doctors recommend taking 5000 to 10,000 ius per day. Now I have taken upto 60,000 per day for a month, then a break, in winter from Nov to march I’ve taken 50,000 per day. Ah I here you say/ to much. Yes it would be/ if I didn’t take Super Vit K2. You see most Doctors do not have a clue/ I mean about Vit K2. My Doctor said I’m taking to much D3. I said what about K2. Hadn’t a clue about K2 and I told him so. Vit K2 keeps the Calcium in the bones. I am very healthy at 62. Just signed up for a Tough Mudder type test. in Oct. Vit D3 heals allsorts of ailments. Read Jeff Bowels book on very large doses of Vit D3. Brilliant book on Vit D3. Yours Tony. UK

      • Although Vitamin D is a good thing, you can still get too much of it. I recently had a patient brought to me by the family with concerns about his weakness and sudden change in mentation. He was forgetting things and at the time of the visit, extremely weak, diarrhea, no longer can walk. This is an 80 year old man who takes care of himself, gardens daily, drives, etc, yet he’s sitting in a wheelchair in front of me and we could barely get him on the exam table. Because of the issues he was having we were concerned about a cancer. We did labs and his calcium was high, PTH low, so now we’re definitely thinking cancer. However, I also did some further digging and questioned every single thing he takes and it turns out he’s taking 50,000 iu Vitamin D a day. The lab shows his Vitamin D level at 130. After having him stop the Vitamin D he showed remarkable improvement in all aspects and I just saw him earlier this week (2 month follow up) and he’s doing excellent. Gained weight, walking strong, driving again. Completely different person. All of his labs have returned to normal except the Vitamin D, which is still high. So make sure you’re seeing a clinician to follow you and make sure you don’t take too much.

        • Thank you Mike!

          I measured my mom’s vitamin D level (13 nmol’s) and decided to put her on 50’000IU of Vitamin D3 daily with 500mcg of vitamin K2 (mk4 and 7) for one month. I want to raide the nmol level to 200. I am also closely monitoring Magnesium and Calcium serum. The reason for doing this is that she was diagnosed with a malignant tumor in the intestine. After one month, I will have another blood test done to see if she reached the mentioned level.

      • My husband recently went for his annual checkup and his doctor tole him his vitamin D was low and he should supplement with massive doses for a short time and then take more moderate for life. Due to the fact that my doctor made a similar recommendation a few years ago and i ended up with severe vitamin D toxicity and almost died, my husband requested that his total vitamin D levels (D25 and D1,25 not just D25) be tested. The clinic was completely baffled by this request and really didn’t know how to proceed, but finally figured out a way they could do the test. The result was that his D levels were already high and he should not take any supplements. unfortunately most doctors and other practitioners are completely unaware of the need to determine total vitamin D before recommending vitamin D supplements.

        • To Terry (or anyone familiar with the subject):
          Could you tell me how your toxicity was treated? How long it took you to get out of it?

          I have the same problem. I can’t take any dose of D3, or I become toxic: I have stomach pains, depression, anxiety, fatigue, high pulse, sweating, insomnia. After taking magnesium or calcium, it even gets worse (they’re vitamin D agonists, the same as vitamin K). My 25(OH)D3 is still low, 1,25(OH) was high-end normal, but I found out that the sample wasn’t frozen and it should be! So it’s much higher in reality.

          I feel awful, and I don’t know how to get out of it. I’m going to try vitamin D/calcium antagonists like vitamin A, C, B6 or zinc but it will take a while anyway.

          My theory is that people with 1,25(OH) toxicity have already high 1,25(OH) levels for some reason or cholecalciferol is metabolized by CYP2D6. I’m slow metabolizer, and if any med I’m taking is metabolized by CYP2D6, I got toxicity symptoms since day one. I need to take a quarter of the therapeutic dose so my body could use this medicine correctly. On the other hand, fast metabolizers need to take 4x of the therapeutic dose. It would explain why doses of D3 varies so much in people’s statements. Of course, it’s a fat-soluble vitamin, so weight is an important factor when you adjust the dose, but the pace of your’s liver metabolization is even more important IMO.

          To people reacting poorly to D3 suplementation: try tiny dose (like 250 IU’s) and monitor your 1,25(OH) levels.

          I feel better in the summer when my D3 25(OH) levels are higher (12 ng/ml in April vs. 24 ng/ml in July). And I don’t have problems with sunbathing. Maybe it’s because my body can shut down D3 production from the sun when it’s enough, but it can’t when I take D3 orally?

          Poor metabolizers would also explain why attempts to add D3 to food ended up badly, with many cases of toxicity, even when doses were very conservative.

  9. My cholesterol, particularly my triglycerides, have been too low for the last decade (triglycerides around ~39; anything less than 50 is considered malabsorption of fat). Until I went totally gluten free, it took about 8 months for my cholesterol to finally start budging. I’ve been tested for celiac, and it’s always negative (including an endoscopy), so I either am insanely gluten sensitive, or I have Crohn’s related to gluten (my son does have Crohn’s).

    I have never been able to get my D up above 30, and it usually hovers in the teens. When I take most supplements, they’re lanolin based, and I don’t tolerate them at all (constipation, metal taste in mouth, etc). I figured I was magnesium and vitamins A and K deficient in addition to D, so started taking those on a regular basis, and as long as I take CLO based vitamin D, I’m good.

    I haven’t had my D tested in about a year and have been solidly gluten free the whole time, so hoping it’s come up. We’ll see!

    • Missy, Doctors usually assume that if you test low in D25 then you will also be low in D1.25, but for some people this is not true. After years of supplementing with vitamin D3, my tested D25 level never rose above 13. However during all this time my untested D1.25 was going sky high without anyone realizing, and i almost died of vit D toxicity. If you have trouble increasing your D25 level, it could be that you have plenty of D, but that your metabolism has trouble converting the active D1.25 back into storage D25. Get both levels tested to find out your TOTAL vitamin D level.

  10. One part of article did not make sense. Magnesium deficiency in America is rare. It is found in a number of foods: leafy greens, beans, pumpkin seeds, quinoa, oats, flax , squash, fruits etc.

    • But many modern foods have less magnesium in them now than they had just 60 or so years ago.
      The ultra-processing of junk foods combined with intensive farming has led to foods being less nutrient dense.
      AVAILABLE TO US AS A NATION (1940–2002)
      It’s also the case that most research shows that most USA adults consume less than half the magnesium RDA.
      Consuming the daily recommended amounts of dairy products would reduce the prevalence of inadequate micronutrient intakes in the United States
      52.3 % of men and 48.3 % of females falling below adequate magnesium intake.

      • Magnesium deficiency is so actual. And so badly connected to low D. The RDA for magnesium is almost a joke, giving the amount of sugar in a meal and the amount of stress around us.

  11. Found this article interesting. I am in the UK, have Hashimoto’s and adrenal problems. My Vit D levels tested optimal but then I had a 23andme test and came back (VDR-Abnormal receptor for Vitamin D – you could have normal levels, but not benefit form those normal levels. In addition, these SNPs can be made worse by excess Methyl donors). My Functional Medicine Dr put me on this recently and I am wondering if it’s OK. I am just not getting anywhere with my health and don’t want to worsen things.

    Thoughts please?

    • Hi Jennie I hope you dont mind my responding to your comment. I dont know who you are or what treatment or diagnosis your have received from your doctor so I do not want to confuse what you already know or have been instructed to do. If I am telling you how to’suck eggs’ then forgive me. Hashimotos thyroiditis occurs when one of your own body system gets out of this case your own immune system is sending antibodies to attack your thyroid. You also said that you have adrenal issues which is probably related to your thyroid issue. The adrenal gland consists of 2 parts the outer section (cortex) is the gland and the inner section( medulla) is nerve tissue which is connected to the autonomic nervous system. Under stress the brain through the nervous system instructs the adrenal nerve tissue to release sugar into the bloodstream ( secretion of epinephrene. and noraepinephrine) in preparation for an action by the body. Stress response is important for the body ( e.g to run from a hungry tiger ) but once the adrenals are switched on there is nothing to switch them off ( except via acupressure, relaxation, light exercise like walking) so your body could be responding to a stressful event that occurred years ago ( so it is accumulated stress ).

      Symptoms of stress can cause additional fat to accumulate around the stomach ( called saggy belly or pendulous abdomen) which is a survival mechanism by the body to protect your vital organs. Other symptoms include intolerance to slow drivers, people who make mistakes, sleep disorder, salt carvings ( since adrenal stress causes sodium depletion), cravings for acidic foods such as lemons, chocolate etc ( since adrenal stress causes the body to lose acid through the urine ( which should have a PH of 6-6.5 but changes to 4-5 very acidic ). The adrenal stress could lead to muscle break down, restless legs,arthritis, tendonitis ( adrenals begin to lose their anti-inflammatory, anti-allergic properties), pulse rate and blood pressure increases ( due to loss of potassium ). The heart has to work harder causeing neck and shoulder pain, loose skin ( loss of collagen ) and even Vitamin D3 depletion. When the adrenals become 90% burnt out this is the only time it will show up on a blood test.

      The bodies most powerful anti-inflammatory substance Cortisol is released from the adrenals. Both cases of abnormal cortisol secretion ( excess due to a high stress state or too little due to adrenal fatigue) can cause immune system disruption. Cortisol diverts amino acids from the lymph tissue ( which is where part of the immune system resides) causing a disruption of antibody ( immune system response) production giving rise to a subsceptability of viral and bacterial infection ( low immune system response). This causes the thyroid to be attacked by the host and becomes constantly inflammed. Hence the birth of Hyperthyroidism ( Hashimotos disease, or Hypothyroidism – Graves disease ) which are both autoimmmune diseases ( the host body is attacking itself) caused by the adrenal system out of control. A good question to ask yourself is when did all this start ?, because all autoimmune diseases are caused by ( or least triggered by ) stress. The thyroid gland malfunctions by 1. The liver and the gall bladder ( lack of Iodine molecule conversion of T4 to T3), 2. The adrenals ( as it would appear your problem), 3. The Ovaries producing too much oestrogen causing a blockage in the thyroid hormone receptor sites).

      How do we try to fix the 2 problems you have which I believe are interrelated. 1. Fix the stress problem ( lifestyle changes, maybe dietary changes-in my opinion it is essential to take all 90 essential nutrients ( 60 minerals, 16 vitamins,12 amino acids, 2 essential fatty acids) from a whole food organic supplement like LivingFuel ‘Supergreens’ + 10,000 IU of Vitamin D3, 100micrograms of K2 ( from cheese, eggs and especially Natto). In addition, to help you with Hashimotos you need to relieve your thyroid from this immune system bombardment. Dr Royal Lee in the 1930s a brilliant scientist discovered a way of diverting the immune system away from attacking host tissue by ingesting a DNA derived product called Thyroid Thytropin PMG which sits in the stomach and acts as a decoy so the immune system diverts its attack to the PMG product allowing in this case for the thyroid to heal. You can get this product on line. It is made by the company founded by Dr Lee called ‘Standard Process’. I dont know how long you need to take it..I suppose until your symptoms subside.

      As you can read adrenals if allowed to get out of control can create a myriad of problems but do not forget your body is an extremely intelligent organism and should be approached with the utmost respect and awe ( something that most conventional physicians fail to do which is why their average lifespan is 56) and the body is designed for health, is self regulating and self HEALING. But it can only achieve this ideal state if you put the right fuel in. Most people on the planet are in fear of their health because it is this state of being that is instilled by conventional medicine, but as Hippocrates stated around 300bc ‘Let food be thy medicine’. So many people are in fear of cancer but again this is an intelligent response of the body due to chronic nutrient deficiency allowing the body to become imbalanced in terms of PH ( either too alkaline or too acidic ). Nature has a way of treating cancer naturally discovered in 1900 in your country.

      My final word, do not allow anybody to start removing organs, it is unnecessary if you maintain your body properly. I always say that if God wanted us to tinker around with the body he would have put a user manual at the back of the Bible.

      I wish you luck

      best rgds


  12. My vitamin D is generally low (12-24 range). I’ve tried taking vitamin D supplements 3 different times in my life in the last 5 years but get arthritic symptoms.

    The first time I didn’t know about the correlation and I had extreme lower back pain and pain from my right knee down to my ankle. I stopped taking the pills by accident because we got a huge snowstorm and I ran out and could not make it to the store. All my pain went away.

    Thinking it was due to poor quality vitamin D I tried again a few months later. After about 6-8 weeks I started getting the pain in my right leg again, so I stopped.

    After 1-1.5 years I decided to try again. I took 5000 mg for 4-5 months and everything was going fine. Then I began to develop arthritic symptoms. Every joint in my body hurt. Last week I stopped taking them and all my pain went away.

    I’ve talked to doctors about this and they disregard me. They’ve never heard of a correlation, but I’ve tested it 3 different times. I’m just going to stick with my low levels. Something that causes that much pain can’t be good for me.

    • P Chiodo, it would be interesting to know where your level of D1,25 is at. Perhaps it is high and your joint pain is a sign of Vit D toxicity. I learned the hard way that you really shouldn’t supplement with vitamin D unless you check both your D25 and D 1,25 levels, or you risk damaging yourself with toxic levels of D. Doctors routinely check D25 but rarely check D1,25. They assume that if D25 is low then D1,25 will also be low, but this is not true for everyone. Both Quest and LabCorp test for D1,25, but Quest has a good reputation for accurate results on this test, and LabCorp does not. It is important that the sample be handled correctly (being frozen immediately and staying frozen until testing) for accurate results.

      • Our laboratory did a study on the stability of 25 Vit D and found it to be unaffected by exposure to light. As far as the stability of 1, 25 Vit D our lab recommends: Serum 1,25 dihydroxy vitamin D3 is stable for 3 days at room temperature. If however transport time is greater that 24 hours, send frozen.

        Of course for us here in New Zealand as the sample can only be tested in Australia, the serum would have to be frozen…

    • If you are getting pain from vitamin D you may be having a heximer reaction where the vitamin D boosts the immune system and it starts attacking bacteria in the body and this causes inflammation and pain. Also be alert that magnesium, boron, and retinol vitamin A are cofactors with vitamin D, the body uses them along with vitamin D and you likely need to add those as well. The heximer reaction will work itself out given time.

      • Thank you for your information. It’s the first time I’ve received a plausible explanation for my symptoms. Will definitely study this some more.
        Thanks again for taking the time.

    • P.Chiodo, try this: take a good magnesium, copper and B-complex supplement for 2-3 months and the remeasure your D levels. They should have increased. Magnesium is needed in almost every step of the generation of vitamin D. I went through hell trying to supplement D, I stopped and months later, did what I am explaining and my D level was at 45.

  13. I’ve taken vitamin D, in varying amounts, for a few years now, and have had nothing but problems with it.

    I’d read that some people with autoimmune issues are worse on supplemental ‘D,’ and I wanted to add my voice to this observation.

    I’ve tried this experiment at least six times, over a two-year period (with a washout period between each test), and it’s clear that ‘D’ is making me substantially, and predictably, worse.

    Lastly, but certainly not least, I’d like to thank Chris Kresser for writing one of the very best health blogs on the net!

  14. I have been doing for last years 4.000 IU if the day wasn’t sunny to 1.000 IU or even nothing when I spent lots of time in the sun. I can’t say I saw any difference in my health

    • @Gregor “4.000 IU if the day wasn’t sunny … I can’t say I saw any difference”
      That’s not surprising.
      The main chronic conditions low vitamin d3 predisposes to are long latency conditions like cancer, diabetes, dementia, heart disease and obesity.
      Most people don’t show immediate symptoms for these conditions until they are diagnosed.
      It is better to delay the onset of these conditions by slowing their progression by maintaining optimal 25(OH)D.
      Consider those conditions associated with vascular and endothelial dysfunction
      The Vascular Endothelium
      Most of these conditions do not present symptoms immediately. By the time symptoms present and the condition diagnosed, the consequences are serious, even deadly.
      But by keeping the cholecalciferol form of vitamin D3 freely available in significant amounts by daily dosing at intake that maintains 25(OH)D at levels 50ng/ml 125nmol/l or above with DAILY dosing (half-life cholecalciferol 24hrs) we can stabilize the endothelium.
      Dietary Vitamin D and Its Metabolites Non-Genomically Stabilize the Endothelium
      It is also the case that DAILY vitamin D3 at intakes that maintain availability of bioavailable vitamin d3 (including in human milk) also enables the body to better regulate the mycobiome and bacteriome.
      Effects of high doses of vitamin D3 on mucosa-associated gut microbiome
      By reducing pathogenic bacteria/fungi while increasing the number and diversity of commensal forms daily vitamin D3 over time improves the microbiome’s ability to create and absorb micronutrients. There is little point in attempting a paleo style diet without a paleo type gut flora and that requires the25(OH)D level typically measured in indigenous peoples living traditional lifestyles
      The Grassrootshealth D’Action project, where those testing 25(OH)D twice yearly have their levels collecated, shows it’s participants generally require more than 4000iu daily supplemental cholecalciferol to stay at/above 50ng/ml It may be you live nearer the Equator than California but if further from the Equator it may be you just aren’t taking sufficient vitamin d3 daily to stay above the natural 50ngm/ml 125nmol/l level that enables bioavailable cholecalciferol to remain freely available?

  15. The trouble with looking a most research vitamin d studies is they do NOT use DAILY dosing and most do NOT raise 25(OH)D to the level that Vitamin d remains in tissue in it’s basic cholecalciferol form.
    Just recently they have found that porcine adipose tissue stem cells are able to activate cholecalciferol to calcitriol.
    Vitamin D machinery and metabolism in porcine adipose-derived mesenchymal stem cells

    There is also recent research showing how cholecalciferol (in that basic form which has a half-life of just 24 hours helps stabilize the endothelium.
    Dietary Vitamin D and Its Metabolites Non-Genomically Stabilize the Endothelium

    Similarly we have recent research showing how getting 25(OH)D to the level typically found in indigenous peoples enables vitamin d to regulate pathogenic gut flora and increase commensal forms.
    Effects of high doses of vitamin D3 on mucosa-associated gut microbiome vary between regions of the human gastrointestinal tract.

    We have have had thousands of papers on Vitamin d over the years but most of these haven’t taken into account the fact that human milk is only vitamin d replete when the levels typically found in indigenous peoples are attained and maintained.

    If we want the diversity and range of gut flora and the ability of our immune function to produce the natural antimicrobial peptides in the cathelicidin family the we have to ensure sufficient cholecalciferol remains in tissue. That only happens when 25(OH)d is kept at/above 50ng/ml 125nmol/l.
    We have an autocrine and paracrine function for a purpose, basing our research only on the endocrine functions of calcidiol and calcitriol forms of vitamin d3 is missing out on the benefits cholecalciferol has in it’s most basic parental form,

  16. After some months of heavily supplementing with over 10.000IU D3 daily, I got a nasty eye zoster rash. Varicella-zoster virus is a herpes virus like Epstein Barr.

    For some time now I have attributed my rash on my D3 supplementation.

    • I supplemented with 13,000 IU of D3 for years and the highest my blood levels ever got (per testing) was 63 ng/ml. Usually it was in the 50s.

      When it comes to supplements, when I take a zillion mega dosed pills of anything, I am hard pressed to identify any effects at all. Some people seem to be hypersensitive to anything, I’m hyper-IN-sensitive to most things. They might affect blood work but if it wasn’t for that, I would think they were doing nothing at all.

  17. Thanks for the article, but I think Vitamin D access is not good for human body and Is the research still going on. If yes, I want some URLs.

    • I seem to do well at 25ng/ml on 25(OH)D. I’m on no medications and I’m the only one who never gets a cold in our household. When I used to take vit D I would get constipation followed by a headache. I would give up and try again when the next convincing article came out. Eventually I began getting photo sensitivity when I supplemented with Vit D and the last time I tried it, this was combined with a wicked case of vertico. No more for me.

  18. I have had two patients that have come to me from other clinicians with chronic diarrhea that hasn’t been resolved despite probiotics, modern medications, colonoscopy, etc. I checked Vit D OH 25 levels and found both to be toxic (the highest so far at 117). I had them stop their supplementation and after about 3-4 months the diarrhea has resolved. This article had good information and I will also start checking Vit D 1 OH 25 as well as consider checking A and K. Thank you Chris.

    • I have read that Vit D is not toxic if you have enough A and K2? However, am puzzled by Mike’s comment of a patient being overdosed at 117. My husband and I had a vit D test and mine came back as barely adequate at 75 nmols with an ideal range given as 75 to 150. Husband was 81 nmols.