title: Reduced 25-hydroxyvitamin D and risk of Alzheimer's disease and vascular dementia.
abstract: BACKGROUND
  Vitamin D deficiency has been implicated as a risk factor for dementia in several cross-sectional studies. We tested the hypothesis that reduced plasma 25-hydroxyvitamin D (25[OH]D) is associated with increased risk of Alzheimer's disease (AD) and vascular dementia in the general population.
  
  
  METHODS
  We measured baseline plasma 25(OH)D in 10,186 white individuals from the Danish general population.
  
  
  RESULTS
  During 30 years of follow-up, 418 participants developed AD and 92 developed vascular dementia. Multivariable adjusted hazard ratios for AD were 1.25 (95% confidence interval [CI], 0.95-1.64) for 25(OH)D less than 25 nmol/L vs. greater than or equal to 50 nmol/L, and 1.29 (95% CI, 1.01-1.66) for less than the 25th seasonally adjusted 25(OH)D percentile vs. more than the 50th seasonally adjusted 25(OH)D percentile. Multivariable adjusted hazard ratios for vascular dementia were 1.22 (95% CI, 0.77-1.91) for 25(OH)D less than 50 nmol/L vs. greater than or equal to 50 nmol/L, and 1.22 (95% CI, 0.79-1.87) for less than or equal to the 50th vs. more than the 50th seasonally adjusted 25(OH)D percentile. Last, multivariable adjusted hazard ratios for the combined end point were 1.28 (95% CI, 1.00-1.64) for 25(OH)D less than 25 nmol/L vs. greater than or equal to 50 nmol/L, and 1.27 (95% CI, 1.01-1.60) for less than the 25th vs. more than the 50th seasonally adjusted 25(OH)D.
  
  
  CONCLUSIONS
  We observed an association of reduced plasma 25(OH)D with increased risk of the combined end point of AD and vascular dementia in this prospective cohort study of the general population.
authors.affiliation: The Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark.
authors.forename: Shoaib
authors.initials: S
authors.lastname: Afzal
authors.affiliation: The Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark; The Copenhagen City Heart Study, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Herlev, Denmark.
authors.forename: Stig E
authors.initials: SE
authors.lastname: Bojesen
authors.affiliation: The Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Herlev, Denmark; The Copenhagen City Heart Study, Bispebjerg Hospital, Copenhagen University Hospital, Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Herlev, Denmark. Electronic address: Boerge.Nordestgaard@regionh.dk.
authors.forename: Børge G
authors.initials: BG
authors.lastname: Nordestgaard
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood* / Q000453:epidemiology*; D001774:Blood Chemical Analysis; D015140:Dementia, Vascular / Q000097:blood* / Q000453:epidemiology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Alzheimer’s disease; Cohort study; General population; Vascular dementia; Vitamin D