Effect of Vitamin D Replacement on Serum TSH in Women with Anti-TPO Positive Sub-clinical Hypothyroidism

Abstract

Introduction: The coexistence of Sub-Clinical Hypothyroidism (SCH) and vitamin D deficiency is a common problem and may lead to various clinical disorders. Several genetic studies have shown an association between gene polymorphism of Vitamin D receptor and of 1a hydroxylase with autoimmune thyroid diseases. Aim: To evaluate the effects of vitamin D3 replacement on Thyroid-Stimulating Hormone (TSH) and anti-TPO levels in women with SCH. Materials and Methods: This clinical trial was performed on 58 Sub-Clinical Hypothyroidism vitamin D deficient women. Patients were treated with 50,000 unit/week vitamin D3 capsule for eight weeks and TSH, Free thyroxine (FT4) and anti-TPO levels were measured before and after drug administration, using an electrochemiluminescence system. Results: The mean age of the population was 38.02±12.68 years. Vitamin D3 replacement caused serum 25(OH) D3 level correction in SCH patients (p<0.001). Additionally, a significant decrease in anti-TPO and TSH levels were also observed in anti-TPO positive patients (n=29) (p=0.002 and p=0.02, respectively). No significant differences in anti-TPO and TSH levels were seen in anti-TPO negative group (p=0.507 and p=0.447, respectively). Conclusion: The study showed that vitamin D3 replacement may be considered as an effective therapy to reduce TSH and anti-TPO levels in vitamin D deficient SCH patients.