Vitamin D supplementation and cognition

BACKGROUND AND OBJECTIVE Epidemiological studies have suggested that deficiencies of certain nutrients may be related to the development of cognitive decline. As deficiencies in vitamin D have been linked to an increased risk of developing dementia, this study explored the effects of vitamin D supplementation on cognition. METHODS This population based, randomized, double-blind, placebo-controlled trial included Chinese adults 65 years of age or older, living independently and not currently taking vitamin supplementation. All subjects underwent a cognitive assessment at baseline and at six and 12 months. The participants were randomized to take a once daily tablet containing either 400 IU of vitamin D3 or a placebo. Fasting venous blood samples were obtained to determine blood lipid concentration and vitamin D levels. RESULTS At follow-up, Full Scale IQ (P<0.001), Verbal Scale IQ (P<0.001) and Performance IQ (P<0.001) scores were significantly higher in the supplementation group. After adjustment, concentrations of triglyceride, total cholesterol, high density lipoprotein and low-density lipoprotein were found to have decreased in the vitamin D group and increased in the placebo group (P<0.001). CONCLUSION This study of elderly Chinese adults found that daily vitamin D3 supplementation resulted in improved cognitive performance over 12 months.