title: Serum 25-hydroxyvitamin D concentrations in Mid-adulthood and Parkinson's disease risk.
abstract: Low vitamin D levels are common among patients with Parkinson's disease (PD). Experimental evidence further suggests that vitamin D may be protective against PD. The objective of this study was to prospectively assess the association between serum 25-hydroxyvitamin D and PD among 12,762 participants of the Atherosclerosis Risk in Communities Study cohort.
  
  
  
  Serum samples were collected in 1990-1992, and 25-hydroxyvitamin D was measured by liquid chromatography mass spectrometry. A total of 67 incident PD cases were identified through December 31, 2008. The median length of follow-up was 17 years. We used Cox proportional hazards models to obtain hazard ratios and 95% confidence intervals, adjusting for age, sex, and race. We did not find any association between serum 25-hydroxyvitamin D concentrations and PD risk, regardless of how serum 25-hydroxyvitamin D was modeled. Compared with participants with serum 25-hydroxyvitamin D < 20 ng/mL, the hazards ratio for PD was 1.05 (95% confidence interval, 0.58-1.90) for 20-30 ng/mL and 1.14 (95% confidence interval, 0.59- 2.23) for ≥30 ng/mL. Similar results were obtained in sensitivity analyses that included white participants only and that were stratified by the length of follow-up.
  
  
  
  This prospective study lends no support to the hypothesis that vitamin D may reduce the risk of PD. © 2016 International Parkinson and Movement Disorder Society.
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
authors.forename: Srishti
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Lutsey
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
authors.affiliation: Department of Neurology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Medicine (Geriatrics), University of Mississippi Medical Center, Jackson, Mississippi, USA.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Mosley
authors.affiliation: Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
authors.forename: Honglei
authors.initials: H
authors.lastname: Chen
mesh_terms: D000359:Aftercare; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood*; D012306:Risk; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Parkinson's disease; cohort study; vitamin D