title: Vitamin D status and measures of cognitive function in healthy older European adults.
abstract: OBJECTIVE
  Data from human studies that have investigated the association between vitamin D status and cognitive function in elderly adults are conflicting. The objective of this study was to assess vitamin D status (reflected by serum 25-hydroxyvitamin D (25(OH)D)) in older European subjects (n=387; aged 55-87 years) and examine its association with measures of cognitive function.
  
  
  METHODS
  Serum 25(OH)D was assessed using enzyme-linked immunosorbent assay, whereas measures of cognitive function were assessed using a comprehensive Cambridge Neuropsychological Testing Automated Battery (CANTAB).
  
  
  RESULTS
  In all, 12, 36 and 64% of subjects had serum 25(OH)D concentrations <30, <50 and <80 nmol/l, respectively, throughout the year. Serum 25(OH)D was significantly and inversely correlated with four assessments within the spatial working memory (SWM) test parameter (SWM between errors (r=-0.166; P=0.003); SWM between errors 8 boxes (r=-0.134; P=0.038); SWM strategy (r=-0.246; P<0.0001); and SWM total errors (r=-0.174; P<0.003)). When subjects were stratified on the basis of tertiles (T) of serum 25(OH)D (<47.6 (T(1)); 47.6-85.8 (T(2)); and >85.8 (T(3)) nmol/l), fewer errors in SWM test scores occurred in subjects in the third T when compared with the first T (P<0.05-0.084). Stratification by sex showed that these differences between tertiles strengthened (P<0.001-0.043) in the females, but the differences were not significant (P>0.6) in males.
  
  
  CONCLUSIONS
  Vitamin D insufficiency, but not deficiency, is widespread in the older population of several European countries. Low vitamin D status was associated with a reduced capacity for SWM, particularly in women.
authors.affiliation: School of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
authors.forename: K M
authors.initials: KM
authors.lastname: Seamans
authors.forename: T R
authors.initials: TR
authors.lastname: Hill
authors.forename: L
authors.initials: L
authors.lastname: Scully
authors.forename: N
authors.initials: N
authors.lastname: Meunier
authors.forename: M
authors.initials: M
authors.lastname: Andrillo-Sanchez
authors.forename: A
authors.initials: A
authors.lastname: Polito
authors.forename: I
authors.initials: I
authors.lastname: Hininger-Favier
authors.forename: D
authors.initials: D
authors.lastname: Ciarapica
authors.forename: E E A
authors.initials: EE
authors.lastname: Simpson
authors.forename: B J
authors.initials: BJ
authors.lastname: Stewart-Knox
authors.forename: J M
authors.initials: JM
authors.lastname: O'Connor
authors.forename: C
authors.initials: C
authors.lastname: Coudray
authors.forename: K D
authors.initials: KD
authors.lastname: Cashman
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002112:Calcifediol / Q000097:blood*; D003071:Cognition; D003072:Cognition Disorders / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000097:blood / Q000150:complications / Q000453:epidemiology; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests; D009752:Nutritional Status; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000453:epidemiology
chemical_list: D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol