Is There a Connection Between Vitamin D and Hashimoto’s Disease? Does Vitamin D Supplementation Help Heal Hashimoto’s Disease?
Vitamin D has long been established in literature as a highly essential nutrient with benefit to the musculoskeletal system and bone density. It also functions in the body as an immunomodulator, facilitating normal immune system function and improving resistance against certain diseases.
Given this background, one has to wonder if a deficiency in vitamin D would be prevalent among individuals with Hashimoto’s thyroiditis and if so, would supplementation with vitamin D help patients manage the disease or perhaps even prevent it?
PART ONE – Vitamin D Deficiency and Hashimoto’s Disease
Research goes back to 2009 on the first question: is there a connection between vitamin D deficiency and Hashimoto’s disease? The earlier studies either indicated that indeed there was a connection while other studies concluded that there was none at all. How is one to draw a final answer when the outcomes are 180 degrees apart?
Kmiec and Sworczak (2015) reviewed twelve studies published between 2009 and 2014 whereby seven of those studies concluded that there was a connection between lower vitamin D levels and Hashimoto’s thyroiditis while two other studies showed no association and three others were inconclusive.
What was the takeaway message from the Kmiec and Sworczak article?
The authors concluded that no final word on a correlation could be made. It was neither an absolute ‘yes’ nor a definitive ‘no’. They reported:
“…in many points accumulated data are inconclusive, many unresolved questions remain, therefore, it remains necessary to perform further studies that would affect clinical approaches to thyroid disease.”
They went on to state that the idea of vitamin D supplementation being able to influence the levels of antibodies in Hashimoto’s was also inconclusive:
“Moreover, vitamin D supplementation has not affected disease occurrence in intervention studies, as summarized in 2 recent reviews. The associations between vitamin D deficiency and disease may indicate that 25(OH)D is only a marker of ill health (; ).”
Fast forward a few years, and what does the research reveal on whether there is a connection between vitamin D and Hashimoto’s thyroiditis?
Anaraki, et al. (2017) found no association between vitamin D levels and Hashimoto’s thyroiditis.
Boyuk et al. (2016) also reached the same conclusion of no correlation between vitamin D and Hashimoto’s thyroiditis.
In 2018, Botelho, et al. reviewed several studies conducted around the world between 2012 and 2016 that basically led to the findings that an association between vitamin D and Hashimoto’s Thyroiditis “…remain unresolved in literature”.
Some of these included:
D’ Aurizzio, et al. (2015) No differences in vitamin D deficiency in Hashimoto’s thyroiditis patients and healthy controls
Yasmeh et al. (2016) No association of vitamin D deficiency and Hashimoto’s relative to controls
On the contrary,
Sun et al. (2017) revealed Vitamin D levels were inversely correlated with positive TPO-ab and higher D levels were linked to lower TSH in males.
Ma et al. (2015) found that there were lower levels of D in Hashimoto’s thyroiditis patients relative to controls.
Bozkurt et al. (2013) found a direct relationship between vitamin D and Hashimoto’s thyroiditis. He and his colleagues looked at 180 Hashimoto’s thyroiditis patients and 180 controls and found that vitamin D levels were significantly lower in the Hashimoto’s thyroiditis patients compared to the controls. He and his team concluded that the severity of vitamin D deficiency correlated positively with disease time (duration of Hashimoto’s thyroiditis) and higher concentrations of anti-thyroid antibodies, suggesting a potential role of vitamin D in the development of Hashimoto’s thyroiditis and/or its progression to hypothyroidism.
Botelho and colleagues then conducted their own study that included 159 participants whereby there were 88 patients with Hashimoto’s thyroiditis, of which 82 were female (93%). In the control group, there were 71 subjects, 61 of which female (85.9%). Mean‐time of diagnosis of Hashimoto’s thyroiditis was ten years (range 1– 47 years).
Vitamin D levels below 30 ng/dL were found in 59.1% (n= 39) of the control group and in 71.8% (n= 61) of Hashimoto’s thyroiditis group (p= 0.1024).
Botelho and his team concluded that there was no relationship with a clarification:
Lower levels of vitamin D have not been associated with Hashimoto’s thyroiditis, however thyroxine levels were determined as a risk factor for vitamin D insufficiency. Additional studies are warranted to clarify the precise role of vitamin D in autoimmune thyroid disease (autoimmune thyroiditis).
Like Botelho and team’s conclusions, Yasmeh et al. (2016) also found that there was no connection between vitamin D and Hashimoto’s. Yasmeh and his colleagues separated his research groups by gender. The levels of vitamin D for the Hashimoto’s thyroiditis and control groups among the females were significantly different (51.7% vs. 31.1%); however, there was no significant difference in D levels among the male group. Furthermore, the researchers stated that none of the females were actually deficient in vitamin D in the first place! It’s just that the levels were different between the two female groups (Hashimoto’s thyroiditis vs. healthy).
Do we then place emphasis on these two recent studies by Botelho and Yasmeh that show no connection between vitamin D and Hashimoto’s? What did other more recent studies and meta-analyses reveal?
Bakr and Meawed (2017) did find an association between vitamin D and Hashimoto’s thyroiditis. There is not only a positive correlation between the vitamin and autoimmune thyroiditis but also an inverse correlation with thyroid antibodies (anti-TGB and anti-TPO).
Kim (2017) reviewed twenty studies through 2016 and concluded that most studies have shown an association between low vitamin D status in the pathogenesis of autoimmune thyroid diseases, especially Hashimoto’s. He did note, however, “there are only few preliminary interventional studies for Hashimoto’s thyroiditis. Further randomized controlled trials are needed to determine whether there is a causal relationship, and investigate the potential application of vitamin D in the treatment of autoimmune thyroiditis.”
Some of the studies he reviewed included the following four:
Evliyaoglu et al. (2015) The prevalence of vitamin D deficiency in Hashimoto’s thyroiditis patients was significantly higher than that in the control group. Blood levels of vitamin D in the Hashimoto’s thyroiditis group was significantly lower compared to the control group. Hashimoto’s thyroiditis was observed 2.28 times more frequently in individuals with vitamin D levels <20 ng/mL.
Kim (2016) concluded that vitamin D insufficiency was significantly more prevalent in 369 patients with autoimmune thyroiditis than in the 407 without autoimmune thyroiditis and higher among the 221 patients with Hashimoto’s thyroiditis than in those with Graves’ Disease or non-autoimmune thyroiditis.
Among Hashimoto’s thyroiditis cases, patients with overt hypothyroidism had a significantly higher prevalence of vitamin D insufficiency and lower vitamin D levels compared with those with euthyroidism and subclinical hypothyroidism or those without autoimmune thyroiditis. Blood levels of vitamin D were significantly negatively correlated with thyroid-stimulating hormone (TSH) levels after adjustment for age, sex, body mass index, and sampling season. This study had an excellent sample size.
Mansournia et al. (2013) found a significant inverse association between vitamin D levels and Hashimoto’s thyroiditis such that each 12.5 nmol/L increase in vitamin D level resulted in a 19% decrease in the odds of Hashimoto’s thyroiditis.
Unal et al. (2014) demonstrated that 254 newly diagnosed Hashimoto’s thyroiditis patients had lower vitamin D levels than 124 healthy controls and vitamin D levels were inversely correlated with anti-thyroglobulin (Tg) and anti-thyroid peroxidase (TPO) antibodies.
Delving further into the research conducted in recent years, and looking beyond those studies that were included in Kim’s meta-analysis, here were other study conclusions drawn that point to a positive correlation between vitamin D levels and Hashimoto’s thyroiditis:
Maciejewski et al. (2015) revealed that serum vitamin D is significantly lower in Hashimoto’s thyroiditis patients vs. controls. He and his colleagues suggested that vitamin D deficiency is one of the risk factors for Hashimoto’s thyroiditis development.
Lionitris and Mazokopakis (2017) concluded that there is an association between vitamin D deficiency and the pathogenesis of Hashimoto’s thyroiditis but also thyroid hypofunction and autoimmunity in general. In summary, the research team’s data demonstrate the association of vitamin D deficiency with Hashimoto’s thyroiditis pathogenesis, thyroid hypofunction and autoimmunity overall.
Sonmegoz et al. (2016) studied a group of 136 Turkish children and determined that the prevalence of a vitamin D deficiency was higher in subjects with Hashimoto’s disease (76%) compared to controls (35%).
Hu and Rayman (2017) concluded that lower vitamin D status was found in Hashimoto’s thyroiditis patients and that there was an inverse relationship between vitamin D with TPO/TG antibodies. They did feel, however, that low vitamin D levels were more likely the result of autoimmune disease processes that included some dysfunction with the Hashimoto’s thyroiditis patients’ vitamin D receptors.
PART TWO – Does Vitamin D Supplementation Help Heal Hashimoto’s Disease?
What are we to conclude with some studies pointing to a “no” but even more studies that seem to conclude with a “yes” in terms of a connection between vitamin D and Hashimoto’s thyroiditis?
Perhaps the studies to date, taken as a whole, still leave the question not completely answered (inconclusive) but have us leaning more towards a positive association.
If we are to consider the possibility of a “yes” and vitamin D’s established role in regulating the immune system, one has to wonder if supplementing with vitamin D could possibly be helpful in an individual who already has Hashimoto’s disease. What would be the impact of vitamin D supplementation on thyroid antibodies which are key markers in measuring autoimmune activity?
Chaudary et al. (2016) – concluded that vitamin D supplementation has a beneficial effect on autoimmunity as seen by significant reductions in thyroid peroxidase (TPO)-ab titers.
He and his team had analyzed 100 newly diagnosed autoimmune thyroiditis patients and found that anti-TPO levels were highest among patients in the lowest vitamin D-level quartile (p = 0.084). At the 3-month follow-up, there was a significant decrease in anti-TPO levels in patients that received vitamin D3 supplementation at 60,000 IU per week for 8 weeks when compared to patients without vitamin D supplementation (46.73% vs. 16.6%; p = 0.028). The number of responders (25% drop in anti-TPO levels) was higher in the group that received vitamin D supplementation (68% vs. 44%; p = 0.015).
Krysiak, et al. (2017) determined that vitamin D was inversely correlated with titers of thyroid antibodies where it was more pronounced for thyroid peroxidase (TPO)-antibodies than for thyroglobulin (Tg) antibodies.
Mazokopakis et al. (2015) found that following 4 months of oral vitamin D3 supplementation (1200–4000 IU/day) in 186 vitamin D-deficient patients with Hashimoto’s thyroiditis, there was a significant decrease (20.3%) in serum anti-thyroid peroxidase (TPO) levels.
Simsek et al. (2016) demonstrated that anti-TPO and anti-Tg levels in autoimmune thyroiditis patients with a 25(OH)D level<50 nmol/L were significantly decreased as a result of administration of vitamin D at 1000 IU/day for 1 month (p = 0.02 and p = 0.03, respectively) .
Ucan et al. (2017) concluded in his study that vitamin D treatment may slow down the development of hypothyroidism. He examined 75 patients with Hashimoto’s thyroiditis; 43 were controls.
Thyroid antibodies were significantly decreased by vitamin D replacement treatment in patients with Hashimoto’s thyroiditis.
Lionitris and Mazokopakis (2017) concluded that the low cost and the minimal side effects of vitamin D supplementation would be prudent for those suffering from Hashimoto’s thyroiditis.
Bakr and Meawed (2017) also recommended that patients with Hashimoto’s thyroiditis receive supplementation with Vitamin D.
Chahardoli et al. (2019) demonstrated in their double-blind and randomized study involving 40 patients that vitamin D supplementation (50,000 IU weekly) can positively impact those with Hashimoto’s thyroiditis by lowering levels of thyroglobulin (Tg) antibodies. While the researchers saw only a small reduction of thyroid peroxidase (TPO) antibodies, those results did not meet the criteria for clinical significance. However, the researchers believed that had the study duration been greater than six months instead of only three months, they would have seen more remarkable reductions in TPO levels in the patients.
Altieri et al. (2017) also believed that supplementation could play a vital role in managing autoimmune thyroid disease but could not really determine the correct levels of vitamin D to supplement since there are so many underlying factors (e.g., sun exposure, diet, etc.).
She and her colleagues, however, did have a baseline of vitamin D to recommend:
“…the optimal 25(OH)D levels to prevent the onset of autoimmune diseases are still under debate. However, authors suggest vitamin D levels higher than 30 ng/mL might be needed in order to reach positive effects.”
She and her research team also added some final notes when it comes to supplementing with vitamin D. They indicated that they would like to see further study on the use of this supplement when managing autoimmune thyroid disease.
“Because of the potential side effect of activated vitamin D, cholecalciferol is the preferred form for supplementation. In comparison to the other inactive forms of vitamin D (vitamin D2 or ergocalciferol), cholecalciferol has a longer plasma half-life and a higher tissue bioavailability.
It appears necessary to evaluate through controlled randomized studies both the best kind of vitamin D compound and the appropriate dose to prevent insufficient vitamin D levels, in order to control the autoimmune mechanisms.”
While there are several studies up to the present that either say there is no connection between vitamin D and Hashimoto’s disease whereas others conclude that there is absolutely an association, there seems to be concurrence among researchers that supplementation with vitamin D does appear to reduce thyroid antibodies in patients who already have Hashimoto’s disease. The only recent study that found no improvement of Hashimoto’s disease with vitamin D supplementation was conducted by Anaraki et al. (2017) but the sample size was small (n=30 treated with vitamin D; n=26 controls) and the follow-up period was of short duration, being only three months. Even the authors recommended “…a larger sample size and longer follow-up and enrolment of people with positive family history of autoimmune thyroiditis as they are more prone to autoimmune thyroiditis and may benefit from potential prevention protocols.”
How much vitamin D should you take?
The above studies used varying doses of 1,000IU and up to much higher doses. I use more conservative doses of 1-2,000IU/day combined with vitamin K. Every patient is different so there isn’t a one size fits all dose for everyone.
It is always best to consult with your trusted physician before taking a new supplement. For right now, supplementation with vitamin D appears to hold promise as one of many things that can be integrated into a healing plan created by one’s physician to manage this illness.