title: The association of serum ionized calcium and vitamin D with adult cognitive performance.
abstract: BACKGROUND
  High serum calcium levels have been associated with cognitive decline in older adults. These associations have not been studied in younger adults. The possible association of vitamin D with cognitive function, independent of calcium, is unknown.
  
  
  METHODS
  A cross-sectional study of associations of serum ionized calcium and 25-hydroxyvitamin D levels with cognitive function in younger adults (20-59 years) and older adults (60-90 years) was conducted using data from the US third National Health and Nutrition Examination Survey (NHANES III).
  
  
  RESULTS
  Neither serum ionized calcium nor 25-hydroxyvitamin D was associated with cognitive function in either age group. For example, the confounder-adjusted mean difference in reaction time in young adults was 0.00 (95% confidence interval = -0.07 to 0.06) per 1 SD calcium.
  
  
  CONCLUSIONS
  Our results do not support an important role for calcium or vitamin D in cognitive performance in adults.
authors.affiliation: MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Tolppanen
authors.forename: Dylan M
authors.initials: DM
authors.lastname: Williams
authors.forename: Debbie A
authors.initials: DA
authors.lastname: Lawlor
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood*; D002136:Calcium, Dietary; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D014481:United States; D014807:Vitamin D / Q000097:blood*; D055815:Young Adult
chemical_list: D002136:Calcium, Dietary; D014807:Vitamin D; D002118:Calcium