Vitamins and supplements are widely included in many people’s daily routines, with vitamin D being particularly popular. This essential vitamin plays a crucial role in our overall health, especially for bones, teeth, and muscles.
According to the NHS, vitamin D helps control the levels of calcium and phosphate in the body, vital nutrients for maintaining strong bones, healthy teeth, and robust muscles.
Insufficient vitamin D can lead to serious health issues, including bone deformities, such as rickets in children, and osteomalacia, a condition that causes bone pain in adults, due to weakened bones.
Aside from dietary supplements, good sources of vitamin D include exposure to sunlight when outdoors, as well as certain foods like oily fish, red meat, and egg yolks.
In addition to physical health benefits, vitamin D is also thought to support cognitive functioning. A study has indicated a potential connection between higher vitamin D levels in midlife and reduced levels of tau protein, which is a significant marker for Alzheimer’s risk.
Alzheimer’s disease is the most prevalent cause of dementia in the UK.
A study has found that higher vitamin D levels in midlife may be linked to lower tau protein levels, a marker of Alzheimer’s risk (Getty Stock Images)
An April 2026 study published in Neurology Open Access, as reported by Eating Well, followed 793 adults participating in the Framingham Heart Study, who were around 39 years old at the outset and free from dementia.
The researchers assessed vitamin D levels and conducted brain scans approximately 16 years later, concentrating on tau and amyloid beta proteins linked to Alzheimer’s.
They observed that higher vitamin D levels during midlife were associated with lower levels of tau, although no such relationship was noted with amyloid beta.
“These findings suggest higher vitamin D levels in midlife may help protect against the accumulation of tau deposits in the brain,” noted study author Martin David Mulligan. “Conversely, low vitamin D levels could be a modifiable risk factor that might be treated to reduce dementia risk.”
Good sources of vitamin D include direct sunlight on the skin as well as foods like oily fish, red meat and egg yolks (Getty Stock Images)
Tau serves as an essential indicator in dementia research, with lower levels traditionally indicating healthier brain aging.
It’s crucial to understand that while this study identifies a correlation, it does not establish causation. Limitations include that vitamin D levels were assessed only once rather than tracked over time, and other lifestyle factors may have influenced the outcomes, even after adjustments were made.
Nevertheless, midlife is highlighted as a critical window where lifestyle choices can have significant impacts.
Mulligan remarked, “These results are promising, as they propose an association between higher vitamin D levels in early middle age and lower tau burden on average 16 years later.” He emphasized, “Midlife is a time where risk factor modification can have a greater impact.”
