Vitamin D and the risk of dementia and Alzheimer disease

Neurology. 2014 Sep 2;83(10):920-8. doi: 10.1212/WNL.0000000000000755. Epub 2014 Aug 6.

Abstract

Objective: To determine whether low vitamin D concentrations are associated with an increased risk of incident all-cause dementia and Alzheimer disease.

Methods: One thousand six hundred fifty-eight elderly ambulatory adults free from dementia, cardiovascular disease, and stroke who participated in the US population-based Cardiovascular Health Study between 1992-1993 and 1999 were included. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected in 1992-1993. Incident all-cause dementia and Alzheimer disease status were assessed during follow-up using National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria.

Results: During a mean follow-up of 5.6 years, 171 participants developed all-cause dementia, including 102 cases of Alzheimer disease. Using Cox proportional hazards models, the multivariate adjusted hazard ratios (95% confidence interval [CI]) for incident all-cause dementia in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (≥25 to <50 nmol/L) were 2.25 (95% CI: 1.23-4.13) and 1.53 (95% CI: 1.06-2.21) compared to participants with sufficient concentrations (≥50 nmol/L). The multivariate adjusted hazard ratios for incident Alzheimer disease in participants who were severely 25(OH)D deficient and deficient compared to participants with sufficient concentrations were 2.22 (95% CI: 1.02-4.83) and 1.69 (95% CI: 1.06-2.69). In multivariate adjusted penalized smoothing spline plots, the risk of all-cause dementia and Alzheimer disease markedly increased below a threshold of 50 nmol/L.

Conclusion: Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease. This adds to the ongoing debate about the role of vitamin D in nonskeletal conditions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / blood
  • Alzheimer Disease / epidemiology
  • Alzheimer Disease / etiology*
  • Dementia / blood
  • Dementia / epidemiology
  • Dementia / etiology*
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male
  • Proportional Hazards Models
  • Risk Factors
  • United States / epidemiology
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / complications*
  • Vitamin D Deficiency / epidemiology

Substances

  • Vitamin D
  • 25-hydroxyvitamin D