Thyroid UK

Vitamin d deficiency and its association with thyroid disease

Vitamin d deficiency and its association with thyroid disease

With the history of posts related to vitamin D here, I feel no need to say any more...

Int J Health Sci (Qassim). 2013 Nov;7(3):267-75.

Vitamin d deficiency and its association with thyroid disease.

Mackawy AM1, Al-Ayed BM2, Al-Rashidi BM2.

Author information:

1Assistant Professor of Medical Biochemistry, Medical Laboratory Department, Applied Medical Science College, Qassim University, Saudi Arabia.

2Students in the Medical Laboratory Department, Applied Medical Science College, Qassim University, Saudi Arabia.



Vitamin D deficiency is a global health problem, its role as an immune modulator has been recently emphasized. The evidence is increasingly pointing towards vitamin D significant role in reducing the incidence of autoimmune diseases. However, at this time the research on its role in autoimmune and thyroid disease is not conclusive. We aimed to examine the relationship between hypothyroidism and vitamin D deficiency and to clarify the relation between serum calcium levels with hypothyroid disease.


Serum vitamin D (25-OH) levels were measured in 30 patients with hypothyroidism and 30 healthy subjects, utilizing the spectrophotometric method. Vitamin D deficiency was designated at levels lower than 20 ng/ml. Thyroid hormones (TSH, T3 and T4) and calcium levels were evaluated in all participants.


Serum 25(OH) vit D was significantly lower in hypothyroid patients than in controls (t=-11.128, P =0.000). Its level was insignificantly decreased in females than male patients (t=- 1.32, P >0.05). Moreover, serum calcium levels recorded a significant decrease in hypothyroid patients when compared to controls (t= -5.69, P = 0.000).


Our results indicated that patients with hypothyroidism suffered from hypovitaminosis D with hypocalcaemia that is significantly associated with the degree and severity of the hypothyroidism. That encourages the advisability of vit D supplementation and recommends the screening for Vitamin D deficiency and serum calcium levels for all hypothyroid patients.

PMID: 24533019 [PubMed]


Image: Exhibit in the Wisconsin Historical Museum, Madison, Wisconsin, USA.

11 Replies

Yonsei Med J. 2014 Mar 1;55(2):476-81. doi: 10.3349/ymj.2014.55.2.476.

Low serum vitamin d is associated with anti-thyroid peroxidase antibody in autoimmune thyroiditis.

Shin DY, Kim KJ, Kim D, Hwang S, Lee EJ.

Author information:

Division of Endocrinology, Department of Internal Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.


Purpose: The association between autoimmune thyroid diseases (AITDs) and vitamin D deficiency is controversial. We aimed to evaluate the relationship between serum 25-hydroxy-vitamin D3 [25(OH)D3] and anti-thyroid antibody levels.

Materials and Methods: 25(OH)D3, anti-thyroid antibodies, and thyroid function measured in 304 patients who visited the endocrinology clinic were analyzed. The patients were subgrouped into the AITDs or non-AITDs category according to the presence or absence of anti-thyroid antibodies. The relationship between anti-thyroid peroxidase antibody (TPOAb) and 25(OH)D3 was evaluated.

Results: The patients with elevated anti-thyroid antibodies had lower levels of serum 25(OH)D3 than those who did not (12.6±5.5 ng/mL vs. 14.5±7.3 ng/mL, respectively, p<0.001). Importantly, after adjusting for age, sex, and body mass index, a negative correlation (r=-0.252, p<0.001) was recognized between 25(OH)D3 and TPOAb levels in the AITDs group, but this correlation did not exist in the non-AITDs group (r=0.117, p=0.127). 25(OH)D3 level was confirmed as an independent factor after adjusting for co-factors that may affect the presence of TPOAb in the AITDs group.

Conclusion: 25(OH)D3 level is an independent factor affecting the presence of TPOAb in AITDs. The causal effect of 25(OH)D3 deficiency to AITDs is to be elucidated.

PMID: 24532520 [PubMed - in process]

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I can re call seeing in my medical records my Vit D was low (below range) co incidentaly this when I was extremely ill and literally thought I was dying. At this same time the Tsh was in range, however not long after this a new rest revealed high antibodies.

Makes so much sense



Interesting article Rod, thanks for sharing this.

My calcium levels were normal despite a low Vitamin D. I don't know why this is however...

Jo xxx


Very interesting, when I had my first blood test, it not only picked up high TSH level ( 5.240 ) but also my vit D level was

18.1 which is severely deficient ! I am learning a lot on this forum, thanks.



Hi James

18.1! Wow! That is low and I thought mine was the lowest result going at 43.6! :o

Hope you get it sorted soon. Have you tried a Vitamin D supplement at all?

Jo xxx


My Doctor gave me prescription for 4000 i.u D3 tablets daily, been taking them for a few weeks, and don't feel any different lol !

Have to go for a 2nd blood test shortly to recheck my high TSH level.



Sorry to hear that. :(

I didn't realise you could get higher dose D3. I was led to believe Vitamin D3 800IU was the only dose the GP could prescribe as that was what I was on before switching to 3000IU!

I hope you get things sorted out soon.

Jo xxx


Here is an Overview of 32 studies of Thyroid and Vitamin D

It has links to each of the studies.

1 like

Thanks hlahore - more studies on my fav subject!

(thanks too Rod) :D

PS an example of private Vitamin testing and levels


Thanks Rod - interesting study.

Moggie x


Good reading. My calcium is in the middle of the range but my vit d was insufficient. Had to supplement myself.

Jo xx


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