The Effect of Vitamin D on Thyroid Autoimmunity in Levothyroxine-Treated Women with Hashimoto's Thyroiditis and Normal Vitamin D Status

Exp Clin Endocrinol Diabetes. 2017 Apr;125(4):229-233. doi: 10.1055/s-0042-123038. Epub 2017 Jan 10.


Background: Low vitamin D status is associated with autoimmune thyroid disease. Oral vitamin D supplementation was found to reduce titers of thyroid antibodies in levothyroxine-treated women with postpartum thyroiditis and low vitamin D status. Methods: The study included 34 women with Hashimoto's thyroiditis and normal vitamin D status (serum 25-hydroxyvitamin D levels above 30 ng/mL) who had been treated for at least 6 months with levothyroxine. On the basis of patient preference, women were divided into 2 groups, receiving (n=18) or not receiving (n=16) oral vitamin D preparations (2000 IU daily). Serum levels of thyrotropin, free thyroxine, free triiodothyronine and 25-hydroxyvitamin D, as well as titers of thyroid peroxidase and thyroglobulin antibodies were measured at the beginning of the study and 6 months later. Results: There were no significant differences in baseline values between both study groups. 25-hydroxyvitamin D levels inversely correlated with titers of thyroid antibodies. No changes in hypothalamic-pituitary-thyroid axis activity and thyroid antibody titers were observed in vitamin-naïve patients. Vitamin D increased serum levels of 25-hydroxyvitamin D, as well as reduced titers of thyroid antibodies. This effect was more pronounced for thyroid peroxidase than for thyroglobulin antibodies and correlated with their baseline titers. Conclusions: Vitamin D preparations may reduce thyroid autoimmunity in levothyroxine-treated women with Hashimoto's thyroiditis and normal vitamin D status.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Autoantibodies / blood
  • Autoantigens / immunology
  • Autoimmunity / drug effects*
  • Dietary Supplements
  • Female
  • Hashimoto Disease / blood
  • Hashimoto Disease / drug therapy*
  • Hashimoto Disease / immunology
  • Humans
  • Iodide Peroxidase / immunology
  • Iron-Binding Proteins / immunology
  • Middle Aged
  • Thyroid Function Tests
  • Thyroid Gland / drug effects*
  • Thyroid Gland / immunology
  • Thyroxine / therapeutic use*
  • Vitamin D / administration & dosage
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood
  • Vitamin D / pharmacology*
  • Young Adult


  • Autoantibodies
  • Autoantigens
  • Iron-Binding Proteins
  • anti-thyroglobulin
  • Vitamin D
  • 25-hydroxyvitamin D
  • TPO protein, human
  • Iodide Peroxidase
  • Thyroxine