Lower Serum 25-Hydroxyvitamin D Level is Associated With 3 Types of Autoimmune Thyroid Diseases

Medicine (Baltimore). 2015 Sep;94(39):e1639. doi: 10.1097/MD.0000000000001639.

Abstract

Autoimmune thyroid diseases (AITD) are common autoimmune disorders. A few studies have analyzed the association between serum vitamin D levels and AITD, and available data remain inconclusive. The aim of this study was to evaluate the association between serum vitamin D levels and 3 types of AITD, that is Graves' disease (GD), Hashimoto's thyroiditis (HT), and postpartum thyroiditis (PPT). Two independent case-control studies were designed. The first is a cross-sectional case-control study in which we examined the levels of 25(OH)D in patients with newly diagnosed GD or HT and in controls; the second is a nested case-control study in which we compared 25(OH)D levels in 610 women who developed PPT during the follow-up after delivery and those who did not. Compared with the controls, GD patients and HT patients had significantly lower 25(OH)D levels. PPT cases also had a lower serum 25(OH)D concentration than controls. Serum 25(OH)D levels were associated with neither antithyroid peroxidase antibody nor antithyroglobulin antibody in GD and HT. There was no significant relationship between thyroid-stimulating hormone and 25(OH)D levels. Every 5 nmol/L increase in serum 25(OH)D concentrations was associated with a 1.55-, 1.62-, and 1.51-fold reduction in GD, HT, and PPT risk, respectively. We observed a lower serum vitamin D levels in AITD patients compared with controls. The lower the vitamin D level is, not vitamin D deficiency per se, the higher the risk for developing AITD will be. However, vitamin D does not have strong association with the titers of thyroid antibodies or the levels of thyroid hormones.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Autoantibodies / blood
  • Case-Control Studies
  • Cross-Sectional Studies
  • Female
  • Graves Disease / blood*
  • Hashimoto Disease / blood*
  • Humans
  • Male
  • Middle Aged
  • Postpartum Thyroiditis / blood*
  • Receptors, Thyrotropin / blood
  • Receptors, Thyrotropin / immunology
  • Thyroid Hormones / blood
  • Thyroid Hormones / immunology
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Young Adult

Substances

  • Autoantibodies
  • Receptors, Thyrotropin
  • Thyroid Hormones
  • anti-thyroglobulin
  • Vitamin D
  • 25-hydroxyvitamin D