Association between serum 25(OH) vitamin D and the risk of cognitive decline in older women

J Gerontol A Biol Sci Med Sci. 2012 Oct;67(10):1092-8. doi: 10.1093/gerona/gls075. Epub 2012 Mar 27.

Abstract

Background: Results of prospective studies examining the association between 25 hydroxyvitamin D (25[OH]D) levels and cognitive decline have been inconsistent. We tested the hypothesis that lower 25(OH)D levels are associated with a greater likelihood of cognitive impairment and risk of cognitive decline.

Methods: The study is a cross-sectional and longitudinal analysis of a prospective cohort of 6,257 community-dwelling elderly women followed for 4 years. Global cognitive function was measured by the Modified Mini-Mental State Examination and executive function was measured by Trail Making Test Part B (Trails B). Cognitive impairment at baseline was defined as a score >1.5 SD below the sample mean; cognitive decline was defined as decline from baseline to follow-up >1 SD from mean change in score.

Results: Women with very low vitamin D levels had an increased odds of global cognitive impairment at baseline: odds ratio (95% confidence interval), 1.60 (1.05-2.42) for women with 25(OH)D <10 ng/mL (25 nmol/L) compared with those with 25(OH)D levels ≥30 ng/mL (75 nmol/L). Compared with women with baseline 25(OH)D level ≥30 ng/mL (75 nmol/L), women with lower levels had an increased risk of global cognitive decline: odds ratio (95% confidence interval), 1.58(1.12-2.22) for women with levels <10 ng/mL (25 nmol/L), and 1.31 (1.04-1.64) for those with levels 10-19.9 ng/mL (25-49 nmol/L). Levels of 25(OH)D were not associated with executive cognitive function.

Conclusions: Low 25(OH)D levels among older women were associated with a higher odds of global cognitive impairment and a higher risk of global cognitive decline.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / blood*
  • Aging / psychology*
  • Cognition Disorders / blood
  • Cognition Disorders / etiology
  • Cognition*
  • Cohort Studies
  • Cross-Sectional Studies
  • Executive Function
  • Female
  • Humans
  • Longitudinal Studies
  • Odds Ratio
  • Prospective Studies
  • Risk Factors
  • United States
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood

Substances

  • Vitamin D
  • 25-hydroxyvitamin D