title: Vitamin D status and its association with gradual decline in cognitive function.
abstract: OBJECTIVE
  To compare plasma vitamin D concentrations among patients with normal cognitive function (control group), mild cognitive impairment (MCI), and Alzheimer disease (AD).
  
  
  METHODS
  In total, 158 patients with AD, 228 patients with MCI, and 603 control subjects were included. Plasma levels of 25-hydroxyvitamin D were measured after comprehensive geriatric assessment and compared among groups. SPSS 15.0 was used for statistical analysis.
  
  
  RESULTS
  Mean levels of 25-hydroxyvitamin D were significantly different among the 3 groups of AD patients, MCI patients, and controls (P < 0.001). Post hoc analysis revealed that the levels were significantly lower in the MCI group than the control group (P = 0.002) and significantly lower in the AD group than the control group (P = 0.003). Multivariate analysis showed that age (OR: 1.070, 95% CI: 1.025-1.116, P = 0.002), instrumental activities of daily living score (OR: 0.920, 95% CI: 0.850-0.995, P = 0.037), 25-hydroxyvitamin D level (OR: 0.959, 95% CI: 0.932-0.987, P = 0.004), and diabetes mellitus (OR: 2.476, 95% CI: 1.153-5.319, P = 0.020) were factors independently associated with AD.
  
  
  CONCLUSIONS
  This study demonstrated that there is a correction between plasma 25-hydroxyvitamin D levels and cognitive functions.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Yeşil
authors.forename: Mehmet Emin
authors.initials: ME
authors.lastname: Kuyumcu
authors.forename: Özgür
authors.initials: Ö
authors.lastname: Kara
authors.forename: Burçin
authors.initials: B
authors.lastname: Halaçli
authors.forename: Sezgin
authors.initials: S
authors.lastname: Etgül
authors.forename: Muhammet Cemal
authors.initials: MC
authors.lastname: Kizilarslanoğlu
authors.forename: Burcu Balam
authors.initials: BB
authors.lastname: Yavuz
authors.forename: Münevver
authors.initials: M
authors.lastname: Özcan
authors.forename: Meltem Gülhan
authors.initials: MG
authors.lastname: Halil
authors.forename: Eylem
authors.initials: E
authors.lastname: Sahin Cankurtaran
authors.forename: Mustafa
authors.initials: M
authors.lastname: Cankurtaran
authors.forename: Servet
authors.initials: S
authors.lastname: Arioğul
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood*; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D