title: Relative vitamin D insufficiency in Hashimoto's thyroiditis.
abstract: BACKGROUND
  Vitamin D insufficiency, defined as serum levels of 25-hydroxyvitamin D [25(OH)D3] lower than 30 ng/mL, has been reported to be prevalent in several autoimmune diseases such as multiple sclerosis and type 1 diabetes mellitus. The goal of the present study was to assess whether vitamin D insufficiency is also a feature of Hashimoto's thyroiditis (HT).
  
  
  METHODS
  We performed a prevalence case-control study that included 161 cases with HT and 162 healthy controls. Serum levels of 25(OH)D3, calcium, phosphorus, and parathyroid hormone were measured in all 323 subjects.
  
  
  RESULTS
  The prevalence of vitamin D insufficiency in HT cases (148 of 161, 92%) was significantly higher than that observed in healthy controls (102 of 162, 63%, p < 0.0001). Among HT cases, the prevalence rate of vitamin D insufficiency showed a trend to be higher in patients with overt hypothyroidism (47 of 50, 94%) or subclinical hypothyroidism (44 of 45, 98%) than in those with euthyroidism (57 of 66, 86%), but the differences were not significant (p = 0.083).
  
  
  CONCLUSIONS
  Vitamin D insufficiency is associated with HT. Further studies are needed to determine whether vitamin D insufficiency is a casual factor in the pathogenesis of HT or rather a consequence of the disease.
authors.affiliation: Department of Endocrinology and Metabolism, Goztepe Education and Research Hospital, Istanbul, Turkey. hgtamer@yahoo.com
authors.forename: Gonca
authors.initials: G
authors.lastname: Tamer
authors.forename: Safiye
authors.initials: S
authors.lastname: Arik
authors.forename: Ismet
authors.initials: I
authors.lastname: Tamer
authors.forename: Damla
authors.initials: D
authors.lastname: Coksert
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D050031:Hashimoto Disease / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D015995:Prevalence; D018417:Th1 Cells / Q000166:cytology; D018418:Th2 Cells / Q000166:cytology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000378:metabolism*; D014808:Vitamin D Deficiency / Q000453:epidemiology / Q000235:genetics*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D010758:Phosphorus; C104450:25-hydroxyvitamin D; D002118:Calcium