title: Serum 25-hydroxyvitamin D and cognitive decline in the very old: the Newcastle 85+ Study.
abstract: OBJECTIVE
  Studies investigating the association between 25-hydroxyvitamin D [25(OH)D] and cognition in the very old (85+) are lacking.
  
  
  METHODS
  Cross-sectional (baseline) and prospective data (up to 3 years follow-up) from 775 participants in the Newcastle 85+ Study were analysed for global (measured by the Standardized Mini-Mental State Examination) and attention-specific (measured by the attention battery of the Cognitive Drug Research test) cognitive performance in relation to season-specific 25(OH)D quartiles.
  
  
  RESULTS
  Those in the lowest and highest season-specific 25(OH)D quartiles had an increased risk of impaired prevalent (1.66, 95% confidence interval 1.06-2.60, P = 0.03; 1.62, 95% confidence interval 1.02-2.59, P = 0.04, respectively) but not incident global cognitive functioning or decline in functioning compared with those in the middle quartiles adjusted for sociodemographic, health and lifestyle confounders. Random effects models showed that participants belonging to the lowest and highest 25(OH)D quartiles, compared with those in the middle quartiles, had overall slower (log-transformed) attention reaction times for Choice Reaction Time (lowest, β = 0.023, P = 0.01; highest, β = 0.021, P = 0.02), Digit Vigilance Task (lowest, β = 0.009, P = 0.05; highest, β = 0.01, P = 0.02) and Power of Attention (lowest, β = 0.017, P = 0.02; highest, β = 0.022, P = 0.002) and greater Reaction Time Variability (lowest, β = 0.021, P = 0.02; highest, β = 0.02, P = 0.03). The increased risk of worse global cognition and attention amongst those in the highest quartile was not observed in non-users of vitamin D supplements/medication.
  
  
  CONCLUSIONS
  Low and high season-specific 25(OH)D quartiles were associated with prevalent cognitive impairment and poorer overall performance in attention-specific tasks over 3 years in the very old, but not with global cognitive decline or incident impairment.
authors.affiliation: Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: A
authors.initials: A
authors.lastname: Granic
authors.forename: T R
authors.initials: TR
authors.lastname: Hill
authors.forename: T B L
authors.initials: TB
authors.lastname: Kirkwood
authors.forename: K
authors.initials: K
authors.lastname: Davies
authors.forename: J
authors.initials: J
authors.lastname: Collerton
authors.forename: C
authors.initials: C
authors.lastname: Martin-Ruiz
authors.forename: T
authors.initials: T
authors.lastname: von Zglinicki
authors.forename: B K
authors.initials: BK
authors.lastname: Saxby
authors.forename: K A
authors.initials: KA
authors.lastname: Wesnes
authors.forename: D
authors.initials: D
authors.lastname: Collerton
authors.forename: J C
authors.initials: JC
authors.lastname: Mathers
authors.forename: C
authors.initials: C
authors.lastname: Jagger
mesh_terms: D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D003072:Cognition Disorders / Q000097:blood* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015995:Prevalence; D012621:Seasons; D006113:United Kingdom / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-hydroxyvitamin D; attention; cognitive decline; cohort study