title: Association between the serum level of vitamin D and systemic sclerosis in a Chinese population: a case control study.
abstract: OBJECTIVE
  Several autoimmune diseases have been associated with reduced vitamin D levels. However, the serum level of vitamin D in Chinese systemic sclerosis (SSc) patients have not been reported. The aim of this study was to evaluate the serum levels of vitamin D in Chinese SSc patients and analyze the association between vitamin D and SSc.
  
  
  METHODS
  25-hydroxy vitamin D125I RIA kit was applied to evaluate the serum levels of vitamin D in 60 SSc patients and 60 healthy controls from Anhui Provincial Hospital, China. The data of epidemiological and clinical characteristics of SSc patients were also collected.
  
  
  RESULTS
  The serum levels of vitamin D were significantly lower in SSc patients than that in healthy controls (26.51 ± 6.27 vs. 36.29 ± 14.24 ng/mL, P < 0.001). The ratio of pulmonary involvement in vitamin D insufficiency patients was higher than that in normal vitamin D patients, but the difference missed statistical significance. The differences in other aspects were not statistically significant in the two groups.
  
  
  CONCLUSIONS
  Serum levels of vitamin D in patients with SSc were lower than that in healthy controls. Further studies are needed to determine whether vitamin D supplement could provide some positive effects.
authors.affiliation: Medical Genetics Center, Anhui Medical College, Hefei, Anhui, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Tian-Ping
authors.initials: TP
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Xiao-Lei
authors.initials: XL
authors.lastname: Huang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Bao-Zhu
authors.initials: BZ
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Ye
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012595:Scleroderma, Systemic / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: fibrosis; pulmonary involvement; systemic sclerosis; vitamin D