Impact of Vitamin D Supplementation on the Level of Thyroid Peroxidase Antibodies in Patients with Autoimmune Hypothyroidism
In spite of studying the relationship between the deficiency and the lack of vitamin D in autoimmune thyroid disorders, the effect of additional administration of the preparations of this vitamin has not been clear in such pathology. The aim of study was to investigate the effect of vitamin D on the content of thyroid peroxidase antibodies (TPO) in patients with newly diagnosed hypothyroidism on the background of autoimmune thyroiditis (AIT). Materials and methods. The study included 52 patients with newly diagnosed hypothyroidism on the background of AIT, who were randomized into two groups. Patients of the first group additionally received cholecalciferol 2000 IU/day (14 000 IU/week) and calcium preparations in a dose of 1000 mg/day for 12 weeks. Patients of the second group were administered only calcium preparations at a dose of 1000 mg/day for 12 weeks in addition to levothyroxine. A positive result of treatment was considered a reduction of antibodies to TPO of at least 25 %. Results. 94.2 % of patients with hypothyroidism had the deficiency and the lack of vitamin D. In patients with hypothyroidism, there was a significant negative correlation between the levels of 25(OH)D and the titer of antibodies to TPO (r = -0.172; p = 0.046). Vitamin D supplementation resulted in a significant decrease of the level of antibodies to TPO (-48.1 %) in patients with hypothyroidism. In general, lowering the level of antibodies to TPO by 25 % or more has been achieved in 73.1 % of patients. Administration of vitamin D contributed to a significant increase of the content of 25(OH)D in the blood serum with a corresponding reduction in the concentration of intact parathyroid hormone in patients with hypothyroidism resulted from AIT. Conclusions. The positive effect of supplemental vitamin D has been established in terms of the level of antibodies to TPO in patients with autoimmune hypothyroidism.