Is Vitamin D Associated With Lower Levels of Alzheimer’s Biomarkers?

In a prospective cohort of 793 nondemented individuals with an average baseline age of 39, researchers measured vitamin D levels and defined >30 ng/mL as high and <30 ng/mL as low. After an average follow-up of 16 years, brain imaging quantified tau and amyloid-beta deposition.

Adjusting for age, sex, and depression, higher midlife vitamin D levels were associated with lower tau protein levels in the brain. No association was found between vitamin D and amyloid-beta deposition.

The authors note tau accumulation may precede amyloid buildup in some brain regions, potentially explaining the differential association. The study’s limitations include a single baseline vitamin D measurement, leaving uncertainty about vitamin D trajectories over time and their relation to later biomarker changes.

Vitamin D is described as a fat-soluble nutrient produced by skin exposure to sunlight, with intake through supplements or foods during low-sun periods, and is implicated in bone health, inflammation, immune function, and glucose regulation.