Vitamin D deficiency and the rise of thyroid disease

Is battling thyroid disease with vitamin D a smart way to go?

Being a patient myself, and knowing well all the grievances of the autoimmune disease I have to live with, I do turn to the vastness of our almighty internet to find the “right” answer to my many questions.

We all have an opinion, a platform to express it and the audience to listen. Unfortunately, when talking about health more often than not, a lot of confusing, wrong and misleading information are found out there. As a result, there are a lot of “this has worked for me” blog posts, personal experiences and testimonials. They are painfully subjective and often lack science in their approach. But their conclusions may not be wrong!

The fact is that not many people have a great, or even a good way to quantify their health experiences, and also to understand many types of influencing or confounding factors that will impact their experimental readout. I am an experimenter myself: I have contemplated long whether I should or not write about my sugar-reducing experience. I decided to do it, as I thought I have included most of the bigger factors impacting me during the experimental time, and it’s a meaningful story for me. However, I can’t be sure in it’s full correctness.


As I am building a platform for a disease management, I am more present on forums, and read more blogs then I did so far. Some are truly amazing, while some others are promoting quirkiness, weirdness and are not very much founded in science. Ideas and recommendations from some (if not all) of them might prove to be true and valid for a certain group of people and they do raise my interest.

Recently, I read about the magic of vitamin D in Hashimoto’s. Whether you decide to try it or not, here are some science facts on vitamin D and Hashimoto’s that are probably good to know.

What is vitamin D?

Vitamin D is a fat-soluble vitamin that is naturally present in very few foods and usually available as a dietary supplement. Our body can produce vitamin D when UV rays trigger its synthesis in the skin. All of vitamin D is not active, and in order to start working it needs to be processed by our liver and our kidneys. At the end of that process we have an active form of vitamin D, called calcitriol [1].

Vitamin D maintains balance of minerals such as calcium, iron, magnesium, phosphate and zinc. Up until recently it was thought vitamin D acts on preserving bone health, but the recent research has demonstrated that it may also play a role in many hormonal diseases, autoimmune diseases as well as cancer [2].

Why do people lack vitamin D, and what to do about it?

Depending on your genes, diet, supplementation and sun/UV exposure vitamin D levels in your body will change.

Although some promising indications have shown vitamin D can help when taken as a supplementary treatment for some autoimmune diseases, it is still not fully clear what is the benefit for autoimmune thyroid disease.

In US, vitamin D supplementation is recommended only for the treatment of conditions caused by the lack of vitamin D [2,3].

Vitamin D deficiency is defined by the US Endocrine Society guideline as less than 20 ng/ml (50 nmol/l), and vitamin D insufficiency between 21 and 29 ng/ml [2,4].

Vitamin D2 or vitamin D3 supplementation can be used if you are low on vitamin D, it might take about eight weeks of treatment to reach the recommended blood levels of vitamin D [4].

How much of vitamin D is safe?

According to the US Endocrine Society guideline, all adults require 600–800 IU (15–20 µg) daily dietary intake of vitamin D.

The upper cutoff to minimize the risk of adverse effects is 100 ng/ml (250 nmol/l) vitamin D [4].

Recommended Dietary Allowances for vitamin D are:

0–12 months → 400 IU (10 mcg)

1–70 years → 600 IU (15 mcg)

>70 years → 800 IU (20 mcg)

Vitamin D and Hashimoto’s

Vitamin D is responsible for anti-inflammatory reaction of our immune system [5–7]. However the mechanism by which it happens is not completely understood. Hashimoto’s is one of a few autoimmune diseases where vitamin D levels were found to be lower compared to the healthy individuals (multiple sclerosis, rheumatoid arthritis, lupus, sclerosis, diabetes, IBS and more) [8].

One of the suggested mechanism connecting vitamin D and Hashimoto’s is through small proteins called cytokines. Cytokines are produced by our own immune cells, and help in communication between different cell types in the body, and many of them are very active during the inflammation (e.g. when virus or bacteria attacks us, or when we get injured). Vitamin D blocks cytokines and through that it prevents inflammation, which is one of the hallmarks of Hashimoto’s development [9].

Research has several hypotheses on how is lack of vitamin D connected to autoimmune diseases:

1. Vitamin D deficiency is one of the environmental triggers for autoimmune diseases [9].

2. Low blood levels of vitamin D will contribute to disease progression [10].

3. Administration of high doses of vitamin D may prevent autoimmune diseases [11].

Hashimoto’s is characterized by a loss of immune balance, which results in a destruction of the thyroid gland by immune cells that mistake own tissue as a target to destroy (similar as when our immune cells try to destroy viruses and bacteria that we acquire). It is mostly a result of genetics, but also of environmental triggers, and one of these triggers might be the lack of vitamin D.

However, the link between Hashimoto’s and vitamin D levels are not fully researched and understood. So far studies have conflicting results. The problem might be that there is a multitude of contributing factors, such as smoking, alcohol, selenium, iodine, stress, infection, medications and many more [12–14] that pollute the results.

Some of the research has shown that variations in four different genes are responsible for the likelihood of developing autoimmune thyroid disease, and are at the same time connected to vitamin D function [15–17]. However, not all of the research has confirmed all the results [18–21].

Research has looked into the direct role of serum vitamin D levels in autoimmune thyroid diseases, but the results are still controversial: while some studies have found lower levels of vitamin D in patients suffering from autoimmune thyroid diseases, the other ones did not find enough evidence for such a claim[9,22–24]. All of the studies were geographically limited, which perhaps offers a very simple (and a naïve) explanation for the confusing and conflicting results. The question remains: in what way vitamin D impacts thyroid disease, and can it’s levels be a good indicator for the stage or progression of the disease?


The research data on the role of vitamin D in autoimmune thyroid diseases are not complete, and the mechanism is not fully understood. Partial blame for this is on the research study design: small number of participants or the fact the data has been collected at one point only, making it difficult for participants to remember many of the past events.

Also, research has to take in consideration the impact of different geographies, seasons, weather conditions, daily sun exposure, BMI, nutrition and heterogeneity of the sample.

Lastly, probably there is some true to the power of vitamin D in treating Hashimoto’s. We do need larger, cleaner and more inclusive data to test this hypothesis. Even when we go global in the research, we might see vitamin D works for a sub-group of Hashimoto’s patients better than for the others. Whatever the results will be, we will learn something beneficial for all of us all over the globe.


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2 Muscogiuri, G. et al. Vitamin D and thyroid disease: to D or not to D? Eur J Clin Nutr 69, 291–296, doi:10.1038/ejcn.2014.265 (2015).

3 Kennel, K. A., Drake, M. T. & Hurley, D. L. Vitamin D deficiency in adults: when to test and how to treat. Mayo Clin Proc 85, 752–757; quiz 757–758, doi:10.4065/mcp.2010.0138 (2010).

4 Holick, M. F. et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 96, 1911–1930, doi:10.1210/jc.2011–0385 (2011).

5 Aranow, C. Vitamin D and the immune system. J Investig Med 59, 881–886, doi:10.2310/JIM.0b013e31821b8755 (2011).

6 Prietl, B., Treiber, G., Pieber, T. R. & Amrein, K. Vitamin D and immune function. Nutrients 5, 2502–2521, doi:10.3390/nu5072502 (2013).

7 Antico, A., Tampoia, M., Tozzoli, R. & Bizzaro, N. Can supplementation with vitamin D reduce the risk or modify the course of autoimmune diseases? A systematic review of the literature. Autoimmun Rev 12, 127–136, doi:10.1016/j.autrev.2012.07.007 (2012).

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10 Kriegel, M. A., Manson, J. E. & Costenbader, K. H. Does vitamin D affect risk of developing autoimmune disease?: a systematic review. Semin Arthritis Rheum 40, 512–531 e518, doi:10.1016/j.semarthrit.2010.07.009 (2011).

11 Schwalfenberg, G. K. Solar radiation and vitamin D: mitigating environmental factors in autoimmune disease. J Environ Public Health 2012, 619381, doi:10.1155/2012/619381 (2012).

12 Effraimidis, G. & Wiersinga, W. M. Mechanisms in endocrinology: autoimmune thyroid disease: old and new players. Eur J Endocrinol 170, R241–252, doi:10.1530/EJE-14–0047 (2014).

13 Hasham, A. & Tomer, Y. Genetic and epigenetic mechanisms in thyroid autoimmunity. Immunol Res 54, 204–213, doi:10.1007/s12026–012–8302-x (2012).

14 Tomer, Y. Mechanisms of autoimmune thyroid diseases: from genetics to epigenetics. Annu Rev Pathol 9, 147–156, doi:10.1146/annurev-pathol-012513–104713 (2014).

15 Mazokopakis, E. E. & Kotsiris, D. A. Hashimoto’s autoimmune thyroiditis and vitamin D deficiency. Current aspects. Hell J Nucl Med 17, 37–40, doi:10.1967/s002449910120 (2014).

16 Muscogiuri, G. et al. Mechanisms in endocrinology: vitamin D as a potential contributor in endocrine health and disease. Eur J Endocrinol 171, R101–110, doi:10.1530/EJE-14–0158 (2014).

17 Feng, M., Li, H., Chen, S. F., Li, W. F. & Zhang, F. B. Polymorphisms in the vitamin D receptor gene and risk of autoimmune thyroid diseases: a meta-analysis. Endocrine 43, 318–326, doi:10.1007/s12020–012–9812-y (2013).

18 Lin, W. Y. et al. Vitamin D receptor gene polymorphisms are associated with risk of Hashimoto’s thyroiditis in Chinese patients in Taiwan. J Clin Lab Anal 20, 109–112, doi:10.1002/jcla.20110 (2006).

19 Stefanic, M., Papic, S., Suver, M., Glavas-Obrovac, L. & Karner, I. Association of vitamin D receptor gene 3'-variants with Hashimoto’s thyroiditis in the Croatian population. Int J Immunogenet 35, 125–131, doi:10.1111/j.1744–313X.2008.00748.x (2008).

20 Yazici, D. et al. Vitamin D receptor gene ApaI, TaqI, FokI and BsmI polymorphisms in a group of Turkish patients with Hashimoto’s thyroiditis. Minerva Endocrinol 38, 195–201 (2013).

21 Maalej, A. et al. Lack of association of VDR gene polymorphisms with thyroid autoimmune disorders: familial and case/control studies. J Clin Immunol 28, 21–25, doi:10.1007/s10875–007–9124–9 (2008).

22 Orbach, H. & Shoenfeld, Y. Vaccination infection and autoimmunity: myth and reality VIAMR 2005–10–26–28, Beau-Rivage Palace Hotel, Lausanne, Switzerland. Autoimmun Rev 6, 261–266, doi:10.1016/j.autrev.2006.09.001 (2007).

23 Goswami, R. et al. Prevalence of vitamin D deficiency and its relationship with thyroid autoimmunity in Asian Indians: a community-based survey. Br J Nutr 102, 382–386, doi:10.1017/S0007114509220824 (2009).

24 Effraimidis, G., Badenhoop, K., Tijssen, J. G. & Wiersinga, W. M. Vitamin D deficiency is not associated with early stages of thyroid autoimmunity. Eur J Endocrinol 167, 43–48, doi:10.1530/EJE-12–0048 (2012).