The effect of Vitamin D treatment on thyroid function and the levels of thyroid autoantibodies, TNF-α, IL-6, IL-1β in patients with autoimmune thyroiditis

Objective : To investigate the relationship between autoimmune thyroid disease and vitamin D treatment. Method : Fifty four (54) patients with both vitamin D deficiency and newly diagnosed euthyroid Hashimoto’s thyroiditis (HT) were recruited for this study. The patients were given intramuscular administration of cholecalciferol at a dose of 300,000 IU/month for 3 months. At the time of diagnoses and after the treatment of vitamin D, free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH), antithyroid peroxidase (anti-TPO), antithyroglobulin (anti-TG), 25 (OH) D3, parathormone (PTH), calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) levels were measured in all patients; TNF-a, IL-6 and IL-1ß levels were measured in only 43 patients. Results: A statistically significant difference (p˂0.05) was observed between the pre and post treatment FT4, TSH, antiTPO, antiTG, PTH and ALP levels. After the treatment of vitamin D, a statistically significant increase was found in 25 (OH) D3 and FT4 levels, and a significant decrease was found in TSH, antiTPO, antiTG, PTH and ALP levels, whereas no significant difference was noted in FT3, Ca, P, TNF- a, IL-6 and IL-1ß levels. Further, levels of vitamin D were not correlated with FT3, FT4, TSH, antiTPO, antiTG, TNF-a, IL-6 and IL-1ß levels (p˃0.05). Conclusions: For patients with both vitamin D deficiency and newly diagnosed HT, treatment of vitamin D had a positive effect on the thyroid antigenicity and thyroid function.