title: Vitamin D and autoimmune thyroid diseases.
abstract: The role of vitamin D as an immune modulator has been emphasized in recent years, and low levels of the hormone were observed in several autoimmune diseases including multiple sclerosis and systemic lupus erythematosus. Vitamin D mediates its effect though binding to vitamin D receptor (VDR), and activation of VDR-responsive genes. While VDR gene polymorphism was found to associate with autoimmune thyroid diseases (AITDs), few studies examined levels of vitamin D in these patients and those that did yielded conflicting results. We therefore undertook to evaluate the levels of vitamin D in patients with AITDs compared to patients with non-AITDs and healthy controls. Serum vitamin D (25-OH) levels were measured in 50 patients with AITDs, 42 patients with non-AITDs and 98 healthy subjects, utilizing the LIAISON chemiluminescence immunoassay (DiaSorin, Saluggia, Italy). Vitamin D deficiency was designated at levels lower than 10 ng/ml. Antithyroid antibodies, thyroid functions and demographic parameters were evaluated in all patients. The prevalence of vitamin D deficiency was significantly higher in patients with AITDs compared with healthy individuals (72% versus 30.6%; P<0.001), as well as in patients with Hashimoto's thyroiditis compared to patients with non-AITDs (79% versus 52%; P<0.05). Vitamin D deficiency also correlated to the presence of antithyroid antibodies (P=0.01) and abnormal thyroid function tests (P=0.059). Significantly low levels of vitamin D were documented in patients with AITDs that were related to the presence of anti thyroid antibodies and abnormal thyroid function tests, suggesting the involvement of vitamin D in the pathogenesis of AITDs and the advisability of supplementation.
authors.affiliation: The Zabludovicz Center for Autoimmune Diseases, Sheba Medical Center, Tel-Hashomer, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Shaye
authors.initials: S
authors.lastname: Kivity
authors.forename: Nancy
authors.initials: N
authors.lastname: Agmon-Levin
authors.forename: Michael
authors.initials: M
authors.lastname: Zisappl
authors.forename: Yinon
authors.initials: Y
authors.lastname: Shapira
authors.forename: Endre V
authors.initials: EV
authors.lastname: Nagy
authors.forename: Katalin
authors.initials: K
authors.lastname: Dankó
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Szekanecz
authors.forename: Pnina
authors.initials: P
authors.lastname: Langevitz
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Shoenfeld
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013967:Thyroiditis, Autoimmune / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics / Q000276:immunology*; D013972:Thyrotropin / Q000378:metabolism; D014807:Vitamin D / Q000097:blood* / Q000276:immunology; D014808:Vitamin D Deficiency / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D014807:Vitamin D; D013972:Thyrotropin