Dietary intake of vitamin D and cognition in older women: a large population-based study.

Abstract

Serum vitamin D concentrations are associated with global cognitive function among older adults. The benefits of vitamin D intake to treat or prevent cognitive impairment remain unknown. The objective of this cross-sectional study was to determine whether weekly dietary intake of vitamin D could be associated with global cognitive performance among older adults. A total of 5,596 community-dwelling women (mean age 80.5 ± 0.1 years) free of vitamin D drug supplements from the Epidémiologie de l'Ostéoporose (EPIDOS) study were divided into 2 groups according to baseline weekly vitamin D dietary intake (either inadequate <35 μg/wk or recommended ≥35μg/wk). Weekly vitamin D dietary intakes were estimated from a self-administered food frequency questionnaire. Cognitive impairment was defined as a Pfeiffer Short Portable Mental State Questionnaire (SPMSQ) score <8. Age, body mass index, sun exposure at midday, season, disability, number of chronic diseases, hypertension, depression, use of psychoactive drugs, and education level were considered as potential confounders. Compared to women with recommended weekly vitamin D dietary intakes (n = 4,802; mean age 80.4 ± 3.8 years), women with inadequate intakes (n = 794; mean age 81.0 ± 3.8 years) had a lower mean SPMSQ score (p < 0.001) and more often had an SPMSQ score <8 (p = 0.002). We found an association between weekly vitamin D dietary intake and SPMSQ score (β = 0.002, p < 0.001). Inadequate weekly vitamin D dietary intakes were also associated with cognitive impairment (unadjusted odds ratio = 1.42 with p = 0.002; full adjusted odds ratio = 1.30 with p = 0.024). Weekly dietary intake of vitamin D was associated with cognitive performance in older women.