학술논문
Vitamin D supplementation and cognition—Results from analyses of the D‐Health trial.
Document Type
Article
Author
Pham, Hai; Waterhouse, Mary; Rahman, Sabbir; Baxter, Catherine; Romero, Briony Duarte; McLeod, Donald S.A.; Armstrong, Bruce K.; Ebeling, Peter R.; English, Dallas R.; Hartel, Gunter; Kimlin, Michael G.; O'Connell, Rachel L.; van der Pols, Jolieke C.; Venn, Alison J.; Webb, Penelope M.; Whiteman, David C.; Almeida, Osvaldo P.; Neale, Rachel E.
Source
Subject
*CONFIDENCE intervals
*INTERVIEWING
*REGRESSION analysis
*VITAMIN D
*DIETARY supplements
*PLACEBOS
*INDEPENDENT living
*RESEARCH funding
*DESCRIPTIVE statistics
*COGNITIVE testing
*STATISTICAL sampling
*LOGISTIC regression analysis
*ODDS ratio
*SECONDARY analysis
*LONGITUDINAL method
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Language
ISSN
0002-8614
Abstract
Background: Observational studies have consistently found a link between low serum 25‐hydroxyvitamin D concentration and higher risk of cognitive impairment. Results from randomized controlled trials have been mixed, and few have been conducted in the general population. Methods: We recruited 21,315 community‐dwelling Australians aged between 60 and 84 years to participate in the D‐Health Trial, a randomized, double‐blind, placebo‐controlled trial. The intervention was monthly oral doses of 60,000 international units of vitamin D or placebo for 5 years. We assessed cognitive function in a randomly sampled group of participants aged ≥70 years using the Telephone Interview for Cognitive Status (TICS) at 2 and 5 years after randomization. The primary outcome for this analysis was TICS score; the secondary outcome was the proportion of people who had cognitive impairment (defined as TICS score ≤25). We analyzed data using mixed models (linear and logistic). Results: We interviewed 3887 participants at year 2 and 3614 participants at year 5. The mean TICS score at these time points was 32.3 and 32.2, respectively. Vitamin D supplementation did not affect cognitive function as measured by TICS score (mean difference between vitamin D and placebo groups 0.04; 95% CI −0.14 to 0.23), or alter risk of cognitive impairment (odds ratio 1.00; 95% CI 0.75 to 1.33). Conclusions: Monthly bolus doses of vitamin D supplementation neither enhanced nor hindered cognitive function among older adults. Population‐wide vitamin D supplementation of older adults that are largely vitamin D replete is unlikely to substantially benefit cognition. [ABSTRACT FROM AUTHOR]