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

Abstract

Background: 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.

Methods: 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.

Results: 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).

Conclusions: Weekly dietary intake of vitamin D was associated with cognitive performance in older women.