Evidence mounts that vitamin D may be key to preventing dementia• https://newatlas.com, By Bronwyn Thompson
Previous research has found that low levels of vitamin D are linked to a higher risk of developing dementia. The hormone helps remove amyloid from the brain – its accumulation is a hallmark of Alzheimer's disease – and it may also assist in preventing tau build-up, another protein at play in the development of dementia.
While vitamin D is obtained through direct sunlight and diet, studies have consistently shown around 40% of Americans to be D-deficient, with the figure higher depending on age and skin color, among other factors.
Researchers looked at the link between dementia and vitamin D supplements in close to 12,400 people who had a mean age of 71 and were dementia-free at the start of the study. Within this group 4,637 took vitamin D supplements.
Of the 2,696 participants who progressed to dementia in the following decade, 75% had no exposure to vitamin D supplements prior to diagnosis. The remaining quarter had baseline exposure at the beginning of the study.
"Our findings give key insights into groups who might be specifically targeted for vitamin D supplementation," said Zahinoor Ismail, lead researcher and professor at the University of Calgary and University of Exeter. "Overall, we found evidence to suggest that earlier supplementation might be particularly beneficial, before the onset of cognitive decline."
Researchers found 40% fewer dementia diagnoses among the 4,637 participants who took vitamin D supplements, compared to the cohort that did not.