Vitamin D and the brain: A possible shield against Alzheimer’s
Medical Advice
Express newspaper
02/04/2026 21:31
A daily dose of vitamin D may help protect against dementia, a new study suggests.
Researchers found that people with higher levels of this vitamin in middle age later had lower levels of a key protein linked to Alzheimer’s in the brain.
This protein, known as tau, is strongly linked to the disease, as its accumulation is believed to influence its development.
“Our results suggest that higher levels of vitamin D in middle age may offer protection against the formation of these tau deposits in the brain,” said Martin David Mulligan of the University of Galway in Ireland. “Low levels of vitamin D may be a risk factor that can be modified to reduce the risk of dementia.”
The study followed 793 people with an average age of 39 who did not have dementia. At the start of the study, all participants had their blood levels of vitamin D measured.
After about 16 years, they underwent brain scans to measure tau and beta-amyloid proteins, both indicators of Alzheimer’s disease.
High vitamin D levels were defined as above 30 nanograms per milliliter — a level that most experts consider sufficient for bone and overall health. About a third of participants had lower levels, while only 5% regularly took supplements.
The researchers also took into account other factors such as age, gender and symptoms of depression, which can affect both vitamin D levels and dementia risk.
The study, published in Neurology Open Access, showed that higher vitamin D levels were associated with less tau protein, but no link was found with beta-amyloid.
“The findings are promising, as they suggest a link between high vitamin D levels in early middle age and lower tau burden 16 years later,” Mulligan added. “Middle age is a period when changing risk factors may have a greater impact.”
One limitation of the study is that vitamin D levels were only measured once.
Often called the “sunshine vitamin,” vitamin D is unique because the body can produce it itself when exposed to sunlight. It acts more like a hormone than a classic vitamin, influencing many body processes.
Health experts recommend that adults over 65 years of age take 10 micrograms of vitamin D every day, especially if they are physically weak, stay home a lot, or get little sunlight.
Over the years, cells gradually become damaged and release substances that promote inflammation, while the body loses its ability to repair itself. This increases the risk of diseases such as cancer, dementia and heart disease.
Scientists are studying whether it’s possible to slow or even reverse this biological aging process. A recent study suggests that taking a daily multivitamin may slow down the body’s “biological clock.”
In this study, older adults who took supplements daily for two years showed slower aging at the cellular level – an effect comparable to reducing biological age by about four months.
The results, published in Nature Medicine, showed that participants taking the multivitamin had slower rates of aging in several DNA-based markers, compared to those who took the placebo.
The study was led by researchers at Massachusetts General Brigham and was based on data from the COSMOS study, a large American project on the effects of supplements on health.
According to scientists, these findings suggest that multivitamins may be a simple and accessible way to support healthier aging, although the benefits remain modest. /GazetaExpress/
