Why Everyone with Celiac Disease Desperately Needs Vitamin D

The Three Heads of Celiac Disease

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.

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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