Neurology Open Access
Vitamin D linked to lower tau brain burden
Clinical takeaway: A common mid-life exposure may shape early Alzheimer’s-related brain changes years later. This study further supports monitoring and maintaining sufficient vitamin D levels for brain health.
Vitamin D is often studied as a potentially modifiable factor in brain aging. This research adds to that by linking higher mid-life vitamin D levels with a lower tau burden years later, while showing no relationship with amyloid beta.
This was a prospective cohort study of Framingham Heart Study Generation 3 participants; 793 dementia-free adults had vitamin D measured at a mean age of 39 years and brain PET scans about 16 years later.
Higher vitamin D was associated with lower tau burden but not reduced amyloid beta. Researchers didn't offer a hypothesis for why the association was seen with one and not the other. Amyloid beta and tau are thought to reflect different aspects of Alzheimer’s disease, with amyloid accumulating over time and tau more closely tied to active neurodegeneration.
Low levels of vitamin D have been linked to cognitive decline in observational studies, though supplementation trials have shown mixed results. Vitamin D influences brain health through effects on inflammation, oxidative stress, and neuronal function.
“Mid-life is a time where risk factor modification can have a greater impact,” summed up study author Martin Mulligan of the University of Galway.
Source: Mulligan MD, et al. Neurology Open Access. April 1, 2026. Association of Circulating Vitamin D in Mid-life With Increased Tau-PET Burden in Dementia-Free Adults