title: Serum vitamin D and the risk of Parkinson disease.
abstract: OBJECTIVE
  To investigate whether serum vitamin D level predicts the risk of Parkinson disease.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  The study was based on the Mini-Finland Health Survey, which was conducted from 1978 to 1980, with Parkinson disease occurrence follow-up through the end of 2007. During the 29-year follow-up period, 50 incident Parkinson disease cases occurred. Serum 25-hydroxyvitamin D level was determined from frozen samples stored at baseline. Estimates of the relationship between serum vitamin D concentration and Parkinson disease incidence were calculated using the Cox model.
  
  
  METHODS
  Three thousand one hundred seventy-three men and women, aged 50 to 79 years and free of Parkinson disease at baseline. Main Outcome Measure Parkinson disease incidence.
  
  
  RESULTS
  Individuals with higher serum vitamin D concentrations showed a reduced risk of Parkinson disease. The relative risk between the highest and lowest quartiles was 0.33 (95% confidence interval, 0.14-0.80) after adjustment for sex, age, marital status, education, alcohol consumption, leisure-time physical activity, smoking, body mass index, and month of blood draw.
  
  
  CONCLUSIONS
  The results are consistent with the suggestion that high vitamin D status provides protection against Parkinson disease. It cannot, however, be excluded that the finding is due to residual confounding and further studies are thus needed.
authors.affiliation: National Institute for Health and Welfare, Helsinki, Finland. paul.knekt@thl.fi
authors.forename: Paul
authors.initials: P
authors.lastname: Knekt
authors.forename: Annamari
authors.initials: A
authors.lastname: Kilkkinen
authors.forename: Harri
authors.initials: H
authors.lastname: Rissanen
authors.forename: Jukka
authors.initials: J
authors.lastname: Marniemi
authors.forename: Katri
authors.initials: K
authors.lastname: Sääksjärvi
authors.forename: Markku
authors.initials: M
authors.lastname: Heliövaara
mesh_terms: D000368:Aged; D005260:Female; D005387:Finland / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000175:diagnosis; D016016:Proportional Hazards Models; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D