According to researchers from the University of Calgary’s Hotchkiss Brain Institute and the University of Exeter, taking the right amount of vitamin D each day can help prevent dementia. Vitamin D is well-known for its benefits in calcium and phosphorus absorption and immune regulation, but it may also play a role in maintaining a sharp mind and cognition. The researchers analyzed the relationship between vitamin D supplementation and dementia among over 12,388 people participating in the U.S. National Alzheimer’s Coordinating Center.
The average age of the participants was 71, and all were dementia-free at the start of the study. Of the group, 37% (4,637) reported taking vitamin D supplements. The researchers found that taking vitamin D was associated with a more extended period of living without dementia. They saw 40% fewer dementia diagnoses in the group taking supplements. Out of the entire sample, 2,696 participants developed dementia over the course of a decade. Of that group, 75% had no exposure to vitamin D prior to their diagnosis, while 25% had baseline exposure.
“Our findings give key insights into groups who might be specifically targeted for vitamin D supplementation. Overall, we found evidence to suggest that earlier supplementation might be particularly beneficial, before the onset of cognitive decline,” says Professor Zahinoor Ismail, the lead researcher.
While vitamin D was effective across all groups, the effects were greater in women and in those with normal cognition, compared to those with mild cognitive impairment. The study also found that taking vitamin D had a greater impact on those who did not carry the APOEe4 gene, which is linked to a higher risk of Alzheimer’s disease. The researchers speculate that this may be due to carriers absorbing vitamin D more efficiently, reducing its supplementation effect. Previous studies have shown that low vitamin D levels can increase dementia risk and that vitamin D may help clear amyloid in the brain, a hallmark of Alzheimer’s disease. Vitamin D may also protect the brain against tau build-up, another protein linked to the development of dementia.
“The link with vitamin D in this study suggests that taking vitamin D supplements may be beneficial in preventing or delaying dementia, but we now need clinical trials to confirm whether this is really the case,” says Dr. Byron Creese, a co-author of the study from the University of Exeter. The ongoing VitaMIND study at the University of Exeter is exploring this issue further by randomly assigning participants to either take vitamin D or a placebo and examining changes in memory and thinking tests over time.
