18/09/2025
A groundbreaking study from Tufts University has found, for the first time, vitamin D present in human brain tissue — and linked it to significantly lower odds of dementia.
Published in Alzheimer’s & Dementia, the research examined vitamin D concentrations in four brain regions tied to Alzheimer’s and other dementias. Analyzing data from 290 elderly participants in the Rush Memory and Aging Project, the study revealed that individuals with higher levels of vitamin D in these brain regions had a 25–33% reduced risk of developing dementia or mild cognitive impairment.
Importantly, this research went beyond blood levels of vitamin D and focused on actual brain concentrations, making it a unique contribution to the field. However, the study was observational, so it cannot establish causation. Most participants were white and the researchers did not account for supplement use, both of which could influence the findings.
Interestingly, while higher vitamin D levels were associated with cognitive resilience, they showed no relationship with common Alzheimer’s markers like amyloid plaques, Lewy bodies, or white matter damage. This suggests that vitamin D may protect the brain through other pathways, possibly vascular ones.
While more diverse, long-term studies are needed, this research opens a promising new avenue in understanding — and potentially preventing — age-related cognitive decline. With Alzheimer’s expected to affect up to 13 million Americans by 2050, identifying protective factors like vitamin D could be vital for future public health strategies.
📄 RESEARCH PAPER
📌 M. Kyla Shea et al, "Brain vitamin D forms, cognitive decline, and neuropathology in community-dwelling older adults.", Alzheimer’s & Dementia (2022)
