EXETER, United Kingdom — The right amount of vitamin D each day can help ward off dementia, according to researchers from the University of Calgary’s Hotchkiss Brain Institute in Canada and the University of Exeter. Probably most well-known for its benefits related to calcium and phosphorus absorption and immune regulation, vitamin D just may turn out to be an integral ingredient when it comes to keeping one’s mind and cognition sharp as well. Study authors analyzed the relationship between taking vitamin D supplements and dementia among over 12,388 people taking part in the U.S. National Alzheimer’s Coordinating Center.
The average age of these participants was 71 and all of them were dementia-free upon initial enrollment. Within the group, 37 percent (4,637) reported taking vitamin D supplements.
Ultimately, the research team found that taking vitamin D displayed an association with living dementia-free for a longer period of time. The team saw 40 percent fewer dementia diagnoses in the group taking supplements. Across the entire analyzed sample, a total of 2,696 participants developed dementia over the course of a decade. Among that group, 2,017 (75%) had no exposure whatsoever to vitamin D throughout all visits prior to receiving a dementia diagnosis, while 679 (25%) had baseline exposure.
“We know that vitamin D has some effects in the brain that could have implications for reducing dementia, however so far, research has yielded conflicting results. 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 research leader Professor Zahinoor Ismail in a university release.
Can vitamin D beat the Alzheimer’s gene?
While Vitamin D proved effective across all groups, researchers note that the effects were significantly greater in women. Similarly, effects were greater in those with normal cognition, as opposed to those who reported signs of mild cognitive impairment (shifts in cognition linked to a higher risk of dementia).
Interestingly, taking vitamin D also appears to have a greater impact on those who do not carry the APOEe4 gene, which studies say increases the risk for Alzheimer’s, the most common form of dementia. Researchers speculate this is due to carriers absorbing vitamin D more efficiently from their intestine, possibly reducing the vitamin D supplementation effect. However, the team did not analyze blood levels to actually test this hypothesis.
Earlier studies tell us that low vitamin D levels can increase dementia risk, and vitamin D may play a role in the clearance of amyloid in the brain. The accumulation of this protein is a hallmark of Alzheimer’s disease onset. Further projects indicate that vitamin D could also help protect the brain against tau build-up, another protein with a strong link to the development of dementia.
“Preventing dementia or even delaying its onset is vitally important given the growing numbers of people affected. 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. The ongoing VitaMIND study at the University of Exeter is exploring this issue further by randomly assigning participants to either take vitamin D or placebo and examining changes in memory and thinking tests over time,” study co-author Dr. Byron Creese from the University of Exeter explains.
The findings appear in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.