Those who took vitamin D supplements were less likely to suffer cognitive impairments, according to an observational study including nearly 12,000 older persons. Several studies suggest a relationship between high vitamin D levels in the brain and enhanced cognitive function.
In addition, prior research has established a link between low vitamin D levels and an increased risk of cognitive deterioration. However, few research has evaluated whether vitamin D supplementation affects the risk of dementia.
In a new study published on March 1 in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, researchers from the University of Exeter in the United Kingdom and the Hotchkiss Brain Institute at the University of Calgary in Canada found that vitamin D supplementation may be associated with a lower risk of dementia.
In particular, they discovered that those who took vitamin D supplements had a lower incidence of dementia than those who did not. The prospective cohort study analyzed data from 12,388 participants in the National Alzheimer’s Coordination Center database. The average age of the participants was 71, and none had dementia at the start of the trial.
The researchers recorded which volunteers had vitamin D exposure and which did not. After adjusting for age, sex, race, education, cognitive diagnosis, depression, and apolipoprotein E (APOE) 4, a gene linked to the development of Alzheimer’s disease, they determined the dementia incidence rates for each participant.
Over 10 years, 2,696 people acquired dementia. 679 of them had taken vitamin D supplements, while 2,017 had no history of doing so. The researchers also discovered that exposure to vitamin D was related with a considerably decreased incidence of dementia in both APOE-carrying and non-carrying individuals. However, the effects were more significant among APOE-negative individuals.
In addition, these results were comparable across three types of supplements: calcium/vitamin D combinations, cholecalciferol (Vitamin D3), and ergocalciferol (vitamin D2). Overall, vitamin D intake was related with a 40% decreased risk of dementia, according to the researchers.
“Our findings shed light on individuals that could be targeted individually for vitamin D supplementation. At the commencement of cognitive impairment, we found evidence that early supplementation could be particularly beneficial. “Professor Zahinoor Ismail of the University of Calgary and the University of Exeter is quoted in a news release as the principal researcher.
Yet, the study had a few shortcomings. For instance, the authors lacked information on vitamin D dosages, making it unclear whether the lower dementia rates were dose dependent. In addition, the study did not evaluate additional supplements that may have contributed to a reduced risk of dementia. Sun exposure, which can enhance vitamin D levels in the body naturally, was not examined.
When recruiting people for future studies, the experts recommend considering disparities in gender, race, sun exposure, and APOE status. In addition, researching how different vitamin D levels affect the risk of dementia could provide insight into how much vitamin D is required for good brain function.
