Endocrine Abstracts

Objective: To investigate vitamin D status in patients with autoimmune hypothyroidism.

Methods: The study group consisted of 100 patients with newly diagnosed Hashimato’s thyroiditis and 100 subjects as the control group. Parameters of calcium metabolism, thyroid function tests and 25(OH) vitamin D levels were measured.

Results or case presentation: Mean age of the study groups was 33.4±4.8 years with female:male, 72:28. Vitamin D insufficiency/deficiency (25(OH)D <30 ng/ml) rate was significantly higher in the Hashimoto’s group compared with the control subjects (75 vs 20%, P<0.0001). In the Hashimoto group, mean 25(OH) vitamin D levels were significantly lower compared with the control group (12.5±7.0 vs 22.3±7.9 ng/ml, P<0.001). The study group revealed higher anti-TPO levels in patients vitamin D deficiency 25(OH)D <20 ng/ml than patients with vitamin D insufficiency group (25(OH)D <30 ng/ml) (650.4±35.4 vs 340.3±65.4 IU/ml, P 0.001). Serum vitamin D level was inversely correlated with the anti-TPO levels (r=−0.30, P=0.007).

Discussion: Vitamin D is involved in immune system and, in particular, on T cell-medicated immunity. Vitamin D receptor is profoundly present in the immature immune cells of thymus and the CD8. Low vitamin D level gives rise to a variety of autoimmune disorders including type 1 diabetes, hypothyroidism.

Conclusion: The higher vitamin D deficiency rates besides lower vitamin D levels in the Hashimoto group together with the inverse correlation between vitamin D and anti-TPO suggest that vitamin D deficiency may have a role in the autoimmune process in Hashimato’s thyroiditis.