Association of Dietary Vitamin D Intake, Serum 25(OH)D3, 25(OH)D2 with Cognitive Performance in the Elderly

Background: As life expectancy increases, cognitive performance decline in the elderly has become one of the major global challenges. We aimed to evaluate the association of dietary vitamin D (VD), serum 25-hydroxyvitamin D3 (25(OH)D-3), 25-hydroxyvitamin D2 (25(OH)D-2), and total 25-hydroxyvitamin (25(OH)D) concentration with cognitive performance in older Americans. Methods: The data from the National Health and Nutrition Examination Survey (NHANES), 2011-2014 was used. The cognitive performance was assessed by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word Learning sub-test, Animal Fluency test, and Digit Symbol Substitution Test (DSST). A binary logistic regression model was applied to evaluate the association between VD and cognitive performance, and restricted cubic spline model was adopted to evaluate the dose-response relationship. Results: While comparing to the lowest dietary VD intake group, the multivariate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of the highest dietary VD intake group were 0.51 (0.36-0.72) for the Animal Fluency test score and 0.45 (0.31-0.66) for DSST score, respectively; and those of serum total 25(OH)D and 25(OH)D-3 concentration were 0.68 (0.47-0.97) and 0.62 (0.44-0.86) for DSST score. L-shaped relationships were identified for dietary VD intake, serum total 25(OH)D and 25(OH)D-3 concentration with cognition performance. The associations between dietary VD intake, serum total 25(OH)D and cognitive performance were non-significant when stratified by gender. Conclusions: The study indicates that dietary VD intake, serum total 25(OH)D and 25(OH)D-3 concentration were positively associated with cognitive performance. Further studies are needed to clarify the possible effects of dietary VD intake and serum 25(OH)D-2, 25(OH)D-3 on cognitive performance.

Automated summary

This study aimed to evaluate the association between dietary vitamin D intake and serum vitamin D concentrations with cognitive performance in older Americans. The results showed a positive association between dietary vitamin D intake, serum total 25-hydroxyvitamin D, and cognitive performance, with no significant gender differences in the associations. Further research is needed to clarify the effects of dietary vitamin D intake and specific serum D concentrations on cognitive performance.