Vitamin D reduced dementia by 40%
Vitamin D supplementation and incident dementia: Effects of sex, APOE, and baseline cognitive status
Alberta, Canada Known association, vitamin D deficiency, incident dementia
Role of supplementation is unclear. Prospectively study Associations, vitamin D supplementation and incident dementia N = 12,388 dementia-free people (from the National Alzheimer’s Coordinating Center)
Baseline exposure to vitamin D was considered D+
No exposure prior to dementia onset was considered D−
MCI and depression were both more frequent in the D− group, compared to D+
People taking vitamin D had less MCI and less depression
Adjusted for age, sex, education, race, cognitive diagnosis, depression, and apolipoprotein E (APOE) ε4.
Potential interactions between exposure and model covariates were explored.
Across all formulations,
vitamin D exposure was associated with significantly longer dementia-free survival,
and lower dementia incidence rate than no exposure
Hazard ratio = 0.60
(95% confidence interval:
Vitamin D exposure was associated with 40% lower dementia incidence versus no exposure.
Over 10 year follow up of
2,696 participants progressed to dementia
Among them the 2,696
2,017 (74.8%) had no exposure to vitamin D
679 (25.2%) had baseline exposure
Exposure to vitamin D was associated with significantly higher dementia-free survival
5-year survival for D− was 68.4%
5-year survival for D+ was 83.6%
The effect of vitamin D on incidence rate differed significantly,
Vitamin D effects were significantly greater in females versus males
Vitamin D effects were significantly greater in normal cognition versus mild cognitive impairment.
Vitamin D effects were significantly greater in apolipoprotein E ε4 non-carriers versus carriers.
Vitamin D effects were less significantly apolipoprotein E ε4 carriers. (25% one copy, 3% two copies)
Vitamin D has potential for dementia prevention, especially in the high-risk strata.
Vitamin D deficiency, worldwide prevalence of up to 1 billion.
Mechanism of action
Vitamin D is known to participate in the clearance of amyloid beta (Aβ) aggregates,
one of the hallmarks of Alzheimer’s disease (AD),
and may provide neuroprotection against Aβ-induced tau hyperphosphorylation
Cholecalciferol may be more effective than ergocalciferol