Researchers looked at the link between vitamin D supplementation and dementia in more than 12,388 people with an average age of 71 who were dementia-free at the start of the study. 37% of them supplemented with vitamin D.
The researchers observed that vitamin D supplementation was associated with longer survival from dementia, and 40% fewer cases of dementia were found in individuals who took vitamin D.
Of the total number of participants, 2,696 developed dementia over 10 years, of whom 75% had no vitamin D exposure at all visits before dementia was diagnosed, and 25% had baseline vitamin D exposure.
Although vitamin D is known to have some effects on the brain, which may have some relevance in reducing dementia, research so far has produced conflicting results. This study provides important insights into who may benefit from vitamin D. Researchers have found evidence to suggest that starting supplementation earlier, before signs of cognitive decline appear, may be particularly beneficial.
Although vitamin D was effective in all individuals, a significantly greater effect was observed in women than in men. The effects were also larger in individuals with normal cognition compared to individuals who reported signs of mild cognitive impairment, which are cognitive changes associated with a higher risk of dementia.
Vitamin D exposure was also significantly greater in individuals who did not carry the APOEe4 gene, which has been shown to confer a higher risk of Alzheimer’s compared to non-carriers of the gene. The researchers suggest that individuals carrying the APOEe4 gene absorb vitamin D more efficiently from the gut, which may reduce the effects of vitamin D intake. However, blood levels were not taken to test this theory.
Previous studies have shown that low levels of vitamin D are associated with an increased risk of dementia. Vitamin D is involved in the clearance of amyloids, the accumulation of which in the brain is a hallmark of Alzheimer’s disease. Research has also shown that vitamin D can help protect the brain from the buildup of tau, another protein that plays a role in dementia.
Want to use our images on your website? Right click on the image to paste the code