title: Serum 25-hydroxyvitamin d concentration and risk of dementia.
abstract: BACKGROUND
  High vitamin D status has been hypothesized to protect against dementia. The aim of the current study was to investigate whether serum 25-hydroxyvitamin D (25(OH)D) level predicts dementia risk.
  
  
  METHODS
  The study was based on the Mini-Finland Health Survey. The study population consisted of 5010 men and women, aged 40-79 years, and free of dementia at baseline. During a 17-year follow up, 151 incident cases of dementia (International Classification of Diseases, revision 8, code 290) occurred, according to population registers. Serum 25(OH)D concentration was determined from serum samples frozen at -20 °C and stored at baseline.
  
  
  RESULTS
  Among women, these with higher serum 25(OH)D concentrations showed a reduced risk of dementia. The hazard ratio between the highest and lowest quartiles of serum 25(OH)D was 0.33 (95% confidence interval = 0.15-0.73) in women and 0.74 (0.29-1.88) in men, after adjustment for age, month of blood draw, education, marital status, physical activity, smoking, alcohol consumption, body mass index, blood pressure, plasma fasting glucose, serum triglycerides, and serum total cholesterol.
  
  
  CONCLUSIONS
  The results are in line with the hypothesis that low vitamin D status may be a risk factor for dementia.
authors.affiliation: From the aNational Institute for Health and Welfare, Helsinki, Finland; and bUniversity of Eastern Finland, Kuopio, Finland.
authors.forename: Paul
authors.initials: P
authors.lastname: Knekt
authors.forename: Katri
authors.initials: K
authors.lastname: Sääksjärvi
authors.forename: Ritva
authors.initials: R
authors.lastname: Järvinen
authors.forename: Jukka
authors.initials: J
authors.lastname: Marniemi
authors.forename: Satu
authors.initials: S
authors.lastname: Männistö
authors.forename: Noora
authors.initials: N
authors.lastname: Kanerva
authors.forename: Markku
authors.initials: M
authors.lastname: Heliövaara
mesh_terms: D000328:Adult; D000368:Aged; D003704:Dementia / Q000097:blood* / Q000453:epidemiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D