Why Everyone with Celiac Disease Desperately Needs Vitamin D

The Three Heads of Celiac Disease

As we discussed in my previous article in this series, the foundation of an effective Celiac Disease treatment plan starts with a real food diet that goes beyond gluten-free junk food.

Reversing Celiac Disease is a three-headed monster. We’re up against inflammation, leaky gut, and Gut Dysbiosis. To be brutally honest with you: slaying a three-headed monster takes everything we’ve got.

And supplements are a critical part of “everything we’ve got.”

A word of caution… to supplement literally means, “something added to complete a thing, supply a deficiency, or reinforce or extend a whole.”

Supplements are a “supplement” for a reason. They support the whole of a treatment plan. They plug holes and deficiencies to reinforce what we’re already doing.

Is Leaky Gut Making You Sicker?


So, if you’re reading this and treating Celiac Disease with a gluten-free diet, the truth is supplements aren’t going to help much until you take your treatment plan seriously and stop eating processed foods.

If you’ve got diet handled and you’re ready to take your health to the next level, I’m going to share why everyone with Celiac Disease should take vitamin D.

Vitamin D is Kind of a Big Deal…

Most vitamins in our body come from outside sources like food, but vitamin D is different. We humans make it ourselves. What’s even more interesting is that it’s not really a vitamin, it’s a secosteroid, a hormonal precursor similar to steroids like cortisol, testosterone, and cholesterol.

When UVB light from the sun hits our skin and interfaces with a form of cholesterol called 7-dehydrocholesterol, vitamin D3 (cholecalciferol) is born. But it still has to go through the liver and kidneys to become the activated form of vitamin D we can use, called calcitriol.

Once in the activated form, it can bind to docking stations located in just about every tissue in the body called vitamin D receptors (VDR). In fact, VDR’s are located in the brain, heart, skin, gonads, prostate, breast, and there’s even VDR activation in the intestine, bone, kidney, and parathyroid gland cells.

Why is that important?

It means vitamin D is involved in brain function, cardiovascular health, immune support, bone and joint health, and just about every process critical to keeping us alive.

It’s also considered essential due to a few of these more specific roles:

  • Promoting the mineralization and growth of bones
  • Activating killer T-cells for defense against infections and bacteria
  • Reducing chronic inflammation
  • Modulating the expression of genes that regulate cell proliferation, apoptosis, and differentiation, (suggesting a potential connection to cancer when deficient)

But vitamin D is even more important for people with Celiac Disease…

As it turns out, vitamin D deficiency is common in Celiac Disease[1] and occurs in both autoimmune conditions and IBD. [2]

It’s even more important if you’ve been prescribed corticosteroids like Prednisone. Research shows they can interfere with your body’s utilization of vitamin D, contributing to bone loss and osteoporosis. [3] [4]

Here’s why that’s a problem: vitamin D deficiency feeds two heads of the Celiac Disease monster, leaky gut and inflammation. Let’s start by looking at how vitamin D impacts a leaky gut.

Vitamin D Can Stop Your Intestines From Leaking

Research is beginning to show that vitamin D Deficiency leads to a comprised mucosal barrier[5] and we know that reversing leaky gut is critical to reversing Celiac Disease.

What does vitamin D have to do with leaky gut?

The tight junctions in your small intestine contain an adhesion junction around them that helps regulate what gets in and what stays out. Dr. Tom O’Bryan describes it like a “rubber band” wrapped around the tight junctions that can get too stretched out and lose its elasticity (ability to snap back in place).

Vitamin D plays a critical role in the elasticity of those rubber bands and how well they keep the tight junctions operating normally. [6]

So if you’re deficient in vitamin D, the elastic band holding your tight junctions together doesn’t work properly… allowing foreign material to leak into your body and promoting inflammation.

Vitamin D Helps Put the Fire Out

Vitamin D plays a critical role in modulating the immune system and downregulating inflammation when the fire burning inside gets too hot. [7]

Vitamin D can even inhibit the development of autoimmune diseases like IBD, RA, and MS[8] by down-regulating NF-B activity, increasing IL-10 production and decreasing IL-6, IL-12, IFN- and TNF- production… creating a well tuned immune system that’s much less inflammatory.

The immune system relies heavily on vitamin D to calm it down by regulating T cells and cytokines. When you’re deficient, inflammation rages inside you like an out of control freight train.

The bottom line is: vitamin D deficiency in Celiacs could be making leaky gut and inflammation worse… that’s why I believe it’s the number one supplement for everyone with Celiac Disease.

How to Supplement With Vitamin D

1.  Get tested

The first step to supplementing with vitamin D is to see if you actually need it. Start by ordering a vitamin D, 25 Hydroxy blood test to check your serum levels. It’s a common test that most doctors can order, or you can order it yourself here.

What levels are recommended?

Mark Sisson recommends serum levels between 50-60 ng/mL.

Chris Kresser recommends serum levels between 35-50 ng/mL.

The Vitamin D Council recommends serum levels between 40-80 ng/mL.

If you’re low, it’s time to get some vitamin D in your life.

2.  Get outside

The most natural way to get vitamin D is from the sun – so after you’re done reading this, get outside and get some vitamin D the natural, fun way.

Depending on many factors, like where you live, about 20-30 minutes of afternoon sun with your shirt off will produce 10,000 IU’s (this vitamin D Council article lists all the confounding factors). Or you can use this fancy calculator from the Norwegian institute for Air Research to estimate how many IU’s you’ll get from playing outdoors.

If getting outside isn’t ideal for your lifestyle or testing shows an acute deficiency, supplementing with vitamin D3 is probably your best option.

3.  Get supplementing with vitamin D3

The amount of vitamin D each person needs is very individual. It depends on how long you’re exposed to the sun each day, the time of year, and how well you’re absorbing nutrients from food.

One study found severe cases of Celiac Disease with acute vitamin D deficiency should supplement with 50,000 IUs 1-3 times a week until their gut health improved and proper vitamin D levels were restored. [9]

Mark Sisson recommends 4,000 IUs daily to maintain serum levels between 50-60 ng/mL.

Chris Kresser recommends between 2,000 – 5,000 IUs daily to maintain serum levels between 35-50 ng/mL.

The Vitamin D counsel recommends a minimum of 1,000 IU per 25 pounds of body weight, and adults and adolescents take at least 5,000 IUs a day in the absence of sun exposure.

No matter how much you decide to supplement with, it’s important to keep getting your serum blood levels tested regularly to fine tune the amount you’re taking. It will change based on the time of year, what you’re eating, stress level, how well you’re absorbing nutrients, etc.

What form of vitamin D is the best to take?

Research shows supplementing with vitamin D in the form of D2 is bioequivalent to D3 in maintaining 25-hydroxyvitamin D levels over a 6 week period. [10] However, vitamin D3 is the natural precursor that we produce in our skin, and it’s the form the Vitamin D Council recommends for supplementation.

That said, we both trust Life Extension’s D3 or NOW Foods Vitamin D3. If someone you know has Celiac Disease, please share this information with them to help prevent vitamin D deficiency. It could change the outcome of their treatment plan.

Do you test and track your vitamin D levels? Tell me about your experience supplementing.

– Jordan



1.  Vitamin D deficiency is common in celiac disease, but the actual prevalence of osteomalacia in celiac disease is unknown (level B evidence).


2.  Vitamin deficiencies in general and vitamin D deficiency in particular have been shown to occur among patients with inflammatory bowel disease (IBD)


3.  Osteoporosis is common in patients requiring long-term treatment with glucocorticoids. Careful attention to preventive management may minimize the severity of this serious complication.


4.  Calcium and vitamin D3 prevented loss of bone mineral density in the lumbar spine and trochanter in patients with rheumatoid arthritis who were treated with low-dose corticosteroids.


5.  Therefore, vitamin D deficiency may compromise the mucosal barrier, leading to increased susceptibility to mucosal damage and increased risk of IBD.


6.  1,25-dihydroxy-vitamin D3 [1,25(OH)2D3] markedly enhanced tight junctions formed by Caco-2 monolayers by increasing junction protein expression and TER and preserved the structural integrity of tight junctions in the presence of DSS


7. Vitamin D also down-regulates nuclear factor-B (NF-B) activity, increases IL-10 production and decreases IL-6, IL-12, IFN-, and TNF- production, leading to a cytokine profile which favors less inflammation


8. D-hormone [1,25(OH)2 D3] is an important immune system regulator that has been shown to inhibit development of autoimmune diseases including experimental inflammatory bowel disease (IBD), rheumatoid arthritis (RA), multiple sclerosis (MS), and type 1 diabetes.


9.  In patients with intestinal malabsorption, very large doses of vitamin D (i.e., 50,000 U 1–3 times weekly) may be needed in the early stages of a gluten-free diet until the malabsorptive process has resolved.


10.  A 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.



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Jordan Reasoner

About Jordan Reasoner

Jordan Reasoner is a health engineer and author. He was diagnosed with celiac disease in 2007 and almost gave up hope when a gluten-free diet didn’t work. Since then, he transformed his health using the SCD Diet and started HealthyGut.com to help others naturally heal stomach problems. You can check out his story here and find him on Google+, Facebook or Twitter.

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58 thoughts on “Why Everyone with Celiac Disease Desperately Needs Vitamin D

  1. Avatar

    Hi, I was diagnosed with coeliac disease 2 years ago and have followed the gf diet since then. But in the last year I’ve , at various points, had dry eyes, hives, headaches, depression, diarrhoea and joint problems. i recently was tested for a large number of conditions after seeking help about persistent lower back joint pain and elbow pain and it was found that while I was not anaemic, my iron was low, and my vitamin D was only 32. I’ve started taking D3 now. what I’m worried about is that the supplements won’t be absorbed, for the same reasons the Vitamin D in food and sun isn’t absorbed properly in coeliacs? Do you have any advice on how to ensure it absorbs?!
    Thank you, Lyra

  2. Avatar

    I have been taking vitamin d3 50,000 mg weekly for the past four months. At that time, it did test low, my hair was falling out and I had trouble dealing with anxiety. After taking it for a month, I stopped shedding so much, started to feel…well, more sane. Don’t have trouble making decisions anymore. My gut health is a little more improved, but I still have a bit of a ways to go. I’ve never felt like I have had complete elimination, and realize I really may need to dial down on some more starches, even if they are plant based starches…

  3. Avatar

    I was diagnosed with celiac a year ago. I was later diagnosed with hypothyroid and vitamin D deficiency. I’ve been gluten free for a year but even after taking a prescription D of 50,000 units a week it’s still low. From what I have read from researching, with celiac the body doesn’t absorb proper nutrients for years after cutting gluten out. It has been a rough few years, I haven’t felt like myself at all. My thyroid is also still off even with medication. Still trying to regulate everything. I wake up exhausted and achy. The sad part is I live in Florida, so vitamin D shouldn’t be an issue. Hanging in there! Thank you everyone for sharing and for the article.

    • Avatar

      You’re on the right track Melissa! Hang in there! Aside from being gluten-free and using a D supplement, it is really important that the rest of your diet is low-inflammatory and high-nutrient. A program like our Solving Leaky Gut diet is the foundation for healing the gut. If you have nay more questions, let us know at support@scdlifestyle.com

      Hope you continue to feel better!

  4. Avatar

    I have either CD or a gluten intolerance and have done SCD/GAPS diet for 2 and a half years followed by a paleo type diet. I had seen a lot of improvements but still some lingering issues. I have just managed to get my vit D levels to these sort of levels and have noticed considerable improvements in bone health, teeth, skin, eyes and hoping iron deficiency. I’m hoping I will see further improvements in my gut health as I think it will improve my mucus membrane and gut microbiota. I still have problems with some other foods which I think results from these issues like colon sensitivities to fruit in particular.

  5. Avatar

    Steve and Jordon,

    I’m wondering if sublingual vitamin D3 would be more effective than capsules for someone with IBD. Does sub lingual vitamins aid absorption? Do you have a recommended brand?


  6. Avatar

    My 6 year old daughter was diagnosed with Celiac in May. We went gluten free, but she did not get any relief until a month ago when we found this website and put her on this diet. She is now pain free! We live in New York, and we know she is Vitamin D deficient. Is there a Vitamin D supplement you would recommend in liquid form that is both celiac and SCD compliant?

  7. Avatar

    How important is it to take Vit K with a vit D3 supplement? I have read it is dangerous to take one without the other, so I would love to know from an expert! If we should take vit K, which one (1, 4, 7), or does it matter?

    Thank you!

  8. Avatar

    Hello I was diagnose Celiac in 2007. Been on GF diet ever since but being on GF diet, I still have issues with my health.. Such as I am on Coumadin since 2007. I was diagnose at the same time.. I know kind of odd to find out both around the same time. What i am trying to say here is the chronic inflammation. I have the pain that never goes away after I had the UTI. Its on the right side lower ribs from the front to the back..It’s extremely painful and doctors doesn’t seem to know the solution of the chronic inflammation while I am on Coumadin. I have been taking vitamin b12 and calcium and vitamin d. Went to see Rhuemaloglist and dr wanted to wait till I was finish with prednisone and take a blood test where it will tell me if I have a chronic inflammation. No matter how hard I try to do varies of test to see what exactly what wrong with me .. I am wondering if prednisone helps reduce the swelling of my gall bladder and I was feeling lot better but after it was reduce to 2 pills it all came back.. Why? I was taking 4 tablet for 3 day and then 3 tablet for another three days and then when it got to 2, my right side ribs were hurting so bad!! From the front to back.. They did ultrasound,
    X-ray , blood test.. This Friday will be MRI
    And hope they find something.. Oh one more thing is that almost 2 months ago i had UTI.. Wondered if getting rid of infection takes forever since
    I finish the antibiotic in 10 days as I was on Cipro.. Please share any related info that I provided.. If not sure please don’t hesitate to ask me
    Thank you!!

  9. Avatar

    I too have celiac disease and low vitamin d (9 the last time I checked) I tried supplements,but they made me VERY tired,and caused blurry vision. Im unable to be in the sun enough. Im at a loss.

  10. Avatar

    I’m not so sure.

    High doses of vitamin D in the young seem to induce allergies in later life. Here is a reference: http://www.ncbi.nlm.nih.gov/pubmed/15699498.

    Williams syndrom features high comorbidity with celiac http://www.ncbi.nlm.nih.gov/pubmed/11694549.

    Williams syndrome is typically caused by a deletion of part of chromosome 7 including the WSTF gene. The result is spikes in 1,25-dihydroxy vitamin D and hypercalcemia. http://www.ncbi.nlm.nih.gov/pubmed/21326359

    We give much larger doses of vitamin D to babies (and adults) today than we did 30 years ago and during the last 30 years it seems celiac disease has increased. So I wonder if oral vitamin D may in fact be a factor in initiating celiac.

        • Avatar

          Thank you so much Seth and C T for sharing your vitamin D knowledge in relation to leaky gut, CD, and autoimmune pains. I hope it leads me to find relief from my fibromyalgia.

          Years ago, tired with my fibromyalgia disease I slacked off with taking care of myself. This included quitting my multi-V for about a year. Then the pain went away for 2 years, but I didn’t connect the gone pain with the gone vitamins.

          Long story made short, I may have a problem with the iron or the vitamin D in that supplement.

          If I may suggest to you guys to make a little YouTube video with this news. It might help a lot of us. God Bless both of you, and to Jordan and Steven for this great channel of yours.

  11. Avatar

    After decades of asking UK doctors why I was always tired and had no stamina, I was finally diagnosed with CD by blood test. That was 5 years ago and I am still tired and still have no stamina. Since going on their only treatment, a life-long GF diet, I have realised that I am also intolerant to oats, all dairy, eggs, soya, pears, fructose, ginger etc etc. Most all of these intolerances were also discovered by a food intolerance test undertaken two years ago – not accepted by UK NHS who do not offer any food intolerance tests of their own. Told recently by Consultant to “learn to live with them”. Luckily, I am food trained so can cope insofar as my knowledge takes me. Most people do not have that expertise.

    This site is the only one I have found that appreciates this problem and I am taking more “informed” professional medical assistance which is recommended. My body appears to be riddled with inflammation – gut, arms, lower back especially and I am convinced they are all linked. I am also stopping sugar intake. Eating out requires strict information to venues.

    More research on treatment of CD is required as the vast majority appears to be on diagnosis only and a life-long GF diet is not the whole answer but try telling UK NHS that.

    Would appreciate comments.

  12. Avatar

    Dear Jordan,

    It was very interesting reading this post. I’m in a gluten and dairy free diet for about a month, but my stomach still feels raw inside, actually I get his dull ache in my whole stomach and colon. I wasn’t diagnosed with celiac, I just started the diet out of desperation due to my ill health, 20 + years of eye inflammation (uveitis), anxiety and depression for the past 16 years or more, numbness/tingling in my whole body that lasts for 2-3 months, acne for the past 20 years, and stomach issues (constipation, dull ache, discomfort, etc.) I had the blood tests done for celiac, which came back negative, and also asked for a blood test of my total IgA which was slightly low. I live in Eastern Europe and don’t have access to organic food, so I’m doing my best to eat as healthy as possible, no table sugar, no processed food, no snacks, but I do eat potatoes quite a bit as they’re the only food that I can find here that keeps me full. I eat quite a lot of eggs, and bacon also, and eat quite a lot of dried fruit and bananas. I’m quite tall and thin so I’m trying not to lose too much weight. I’m also taking a low dose of vitamin D, 800 IU every other day (jarrow, it was the only brand I could find here) and I’m taking niacin 1000 mg for my anxiety and depression, but it doesnt seem to be helping much). Could you please give me your opinion about what I’ve written as I have apsolutely no one to talk to and where I live everyone thinks it’s nonsense to go gluten and dairy free.

    • Avatar

      for the celiac blood test you have to be eating gluten. its why i don’t do the test.

      there are many things that could cause your problems and i’ll suggest a couple things that might not be really obvious.

      your elimination diet has not included fruit.

      years after i had been on a gluten and lactose free diet, i discovered that fructose was causing some big remaining problems. it was the last thing i would have thought.

      i no longer eat fruit.

      hemp oil boosts my mood big time. so does magnesium bisglycinate.

      never take a cal-mag.

      magnesium bis. and reducing dairy might change your life of being anxious.

      magnesium speeds transit time as does fiber. magnesium sulphate taken by mouth is a cheap way to get faster transit time and magnesium. start by only taking a really small amount because it can give cramps. small for me is 1 tea spoon.

      too much dairy or calcium makes you repeat the same depressing thoughts. it also makes a person anxious. thats why i take 560 mg magnesium BISGLYCINATE. twice that if i fly so the barking dog or crying baby doesn’t drive me nuts.

      are you getting iodine (anti depressant if not too much) and selenium? use iodized table salt liberally. factory presalted foods are not iodized! low on iodine can lead to over height, surprisingly.

      vitamin d is another anti depressant. it boosts testosterone (an antidepressant). i get 40,000 iu a week by going to a tanning bed with uvb.

  13. Avatar

    Hi Jordan and Steven! I have Celiac and started supplementing with Vitamin D. It’s been 2 weeks now. How long does it take before I can see the effects, especially about the leaky gut? Thank you for all your work, this website is amazing and has helped me a lot.

  14. Avatar

    I would like to see discussion concerning adding organic virgin coconut oil (from Indonesia) to gluten-free and All processed foods-free diet, (salt and caffeine free for heart) that consisted of only extra virgin olive oil in glass and real unsalted butter consumed for years. I realized that gluten-free processed foods contain too much salt and often seemed to contain other irritants as well.

  15. Avatar
    Ursula Stouffer says:

    Thanks for all the great info!

    I’ve been gluten free for seven years now, and still have problems. Millions of intolerances, and I have to take a lot more of my vitamins than normal to have good levels, because obviously I am not absorbing nutrients very well.

    I had celiac symptoms from the age of three, and finally figured it out myself when I was 52 (I will be 60 in May).

    I have to take at least 60,000 IU of vitamin D3 a week to maintain optimal levels.

    And despite NOT eating a lot, and rarely eating those ‘gluten free foods’, I keep gaining weight.

    But as of this week, I’ve been eating nothing but protein (organic meat) and fat (lard and butter mostly), and a very few vegetables…. no fruit, as I don’t tolerate fruit very well. I am also obviously carbohydrate intolerant….. and starch at all makes me sick.

    After reading through several of your previous posts, I realize that my gut must still be in terrible shape, and I have systemic inflammation.

    Thanks so much for your excellent explanations, I am sure it will be very helpful in my journey toward health. You guys are awesome!

    • Avatar

      If you are really bad as you explain, may I suggest you just drink bone broth from beef or chicken bones, homemade with all the gelatin, for several days. Include some chicken or meet from the broth, made in a slow cooker for 24+ hours. When my mother and I (both Celiacs and crohns disease) were at our worst, this healed us and was very nourishing.

  16. Avatar

    Your message is incredibly helpful and I can’t thank you enough. I’ve had many swerves and painful turns on my gluten free journey, the past year. It’s a breath of fresh air to have someone talk some sense who happens to see the big picture! 🙂

  17. Avatar

    Thank you so much for the great information you are providing. I´d like to hear your take on a supplement question. I bought swansons boronchelate to try if it helps with my messed up joints. Unfortunately i didn´t pay enough attention to the ingredients.One major component is rice flour as a filler. Can i still take these? The amount of flour i would ingest is tiny. I´m on a budget so i don´t want to throw it away. What do you guys think?

    Thank you very much

  18. Avatar

    Great article…need to supplement more I know…one question…be careful about the type you get…in most softgels/liquids…glycerin is an ingredient…..which according to your leaky gut article…can make leaky gut worse…a good source for vitamin D3 is ‘Source Naturals’…get the capsules…they do not contain glycerin

    • Avatar

      We use Quick D from Nutristart: http://nutristart.com/products/quick-d/

      It’s in drop form: emulsified liquid.
      Has 950+ drops per bottle (each drop is 1,000IU).
      It’s D3 (from organic sunflower oil)
      Contains no preservatives, colour, sweeteners, wheat, gluten, dairy or yeast.

      We add it to our coffee (4 drops each), would never know it’s there.

      I remember giving our son D3 as a baby (breastfed in Canada) from the drugstore — that stuff was nasty! Wish I knew about the Quick D then.

  19. Avatar

    Thank you for your article. It is a good reminder of a very important factor in keeping healthy.

    I have to say though, that 3-headed dragon is really, really yucky!!1

    • Jordan Reasoner

      That’s a great point. Vitamin D is really important for everyone, even those that don’t have digestive problems or autoimmune conditions. That will have to be another post, but yes, getting tested is the first place to start.


      • Avatar

        Could you comment on the importance of getting all of the fat soluble Vitamins together. That is a Vit D toxicity may be because you do not have enough A. The Vit D is good for your bones, but only if you have enough Vit K2 to direct it to the bones. I think that it is becoming more clear in the literature that it is dangerous to supplement just one of the fat soluble Vits without supplementing all.

  20. Avatar

    I tried supplementing with pills and developed vitamin d toxicity! On a very very low dose. Now I get in the sun every day and use a tanning bed fitted with the correct lights during the winter. I’ve managed to get a level up from 2 to 35


      • Avatar

        I was curious about that also. How can one go from being Vit D deficient, take oral supplement, get toxicity on a very very low dose, and then drop back to a level of 2. It seems something is missing from this equation because my RN training is not understanding the physiological explaination.

        I am not saying that Ressy is not being honest – please – I do not mean it that way. I just think there must be other factors such as what dose Vit D was taken and how many times per day and for how long. And also how long were the low dose Vit D supplements taken before labs were done.

        Just a little confusion and also trying to understand this.

        Thank you

        • Avatar

          “How can one go from being Vit D deficient, take oral supplement, get toxicity on a very very low dose, and then drop back to a level of 2.”

          That actually makes sense if one considers that 1) the human body is accustomed to getting most of its Vitamin D from synthesis in the skin, not ingested into the gut (mode of administration of medications can make a big difference) and 2) we haven’t looked much into vitamin homeostasis (i.e., how the body adjusts to large doses of vitamins over the long term). We know, for instance, that folic acid oversupplementation can cause downregulation of folic acid receptors in the intestines. What if we are doing something similar to our Vitamin D receptors? It is darn near impossible to avoid Vitamin D supplementation if one drinks milk in the USA. Let’s theorize a bit: Person A gets a lot of oral Vitamin D for so long that his body starts making fewer and fewer of those Vitamin D receptors that are so essential to gut health (without them, even probiotics won’t do you a lick of good). He has low Vitamin D in blood serum tests because the body just isn’t absorbing enough, so he takes supplements. Whooops. Megadoses can lead to toxicity if there are already intestinal permeability issues. So he stops. But there are now almost no Vitamin D receptors left due to vitamin homeostasis. Voila. Low intestinal absorption and so low serum vitamin D again.

          It all makes sense if we accept that our bodies adjust to what we give them over time.

          • Avatar


            Thanks for highlighting this. I agree with you that issues of homeostasis and compensatory factors are involved and often unappreciated in vitamin D supplementation. I also appreciate your post above in that it offers a novel explanation for these seemingly contradictory events.

            You suggested: “Person A gets a lot of oral Vitamin D for so long that his body starts making fewer and fewer of those Vitamin D receptors that are so essential to gut health…” This is an interesting hypothesis. Do you by chance have any evidence that the “body starts making fewer and fewer of those Vitamin D receptors” or is your thinking on this primarily by driven by the analogy to folic acid as you mentioned?

            By the way another possible explanation for the low serum levels on supplementation is that they are measuring the wrong metabolite. 25-hydroxy vitamin D is typically measured in serum. Sometimes it is low when the active form 1,25 dihydroxyvitamin D is high and there are other forms that may be high or low as well that have only been measured in research settings.


  21. Avatar

    My three year old son has Celiac, and we think our 15 month old daughter does too. We make an effort to make sure they get some time in the sun everyday.

    Since we control their diet, they are strictly gluten free. We probably won’t be giving them any kind of supplements but would like to make sure they’re getting enough. Any dietary recommendations for increasing D intake?

    • Jordan Reasoner

      Hey Graham, great question. Our friend Chris Kresser said this about getting Vit D from food:

      “Seafood is the only significant source of vitamin D, but you’d still have to eat a lot of it to get enough. 8-9 ounces of herring provides about 2,000 IU of vitamin D, which is a minimum daily requirement for most people to maintain adequate blood levels.”


      Also, in Robb Wolf’s book The Paleo Solution, he states that, “We can obtain Vit-D from certain animal products, such as liver or fortified dairy products, but liver offers several problems, including very high levels of Vit-A.”

      I didn’t get into it with this post, but too much dietary Vit-A can inhibit Vit-D, which is why Robb mentioned that.

      If they’re getting sun everyday, you can use the calculator I linked to in my post to see how many IU’s are possible based on where you live, time of year, etc. Alternatively, you could get their blood serum levels tested, but having kids of my own I know how hard it is to get them pricked with needles unless it’s really important.

      Hope that helps,


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