Summary
Vitamin D supplementation cut dementia risk by 40% in a 12,000-person study. Learn why nearly 70% of Americans are deficient, how age and body fat tank your levels, and the blood markers you should actually be tracking for brain protection.
Key Points
- Nearly 70% of Americans have insufficient vitamin D levels (below 30 ng/mL)
- Vitamin D users had 40% lower dementia risk in 12,388-person study
- Higher vitamin D levels correlate with less white matter brain damage
- Age reduces vitamin D production—70-year-olds make 4x less than 20-year-olds
- Body fat stores vitamin D, reducing bioavailability in overweight individuals
- Sunscreen and darker skin pigmentation reduce vitamin D synthesis
- Northern latitudes have months with no UVB radiation reaching the surface
Key Moments
Vitamin D cuts dementia risk by 40% over a decade
A study of 12,000+ adults found vitamin D supplementation was associated with 40% lower dementia risk over 10 years.
"After just five years, 84% of the vitamin D supplement users were dementia-free compared to 68% of the non-users."
