Exposure to vitamin D supplements is linked to longer dementia-free survival and a lower rate of dementia when compared to no exposure, a new study has found.
Investigators examined the effects of vitamin D on long-term dementia incidence in over 12,000, older participants using data from the National Alzheimer’s Coordinating Center. Study subjects were dementia-free at baseline. Across all formulations, participants exposed to vitamin D had a 40% lower dementia incidence versus those who were determined to have no exposure.
Varied effects
The effects of supplementation varied across groups by sex, cognitive status and genetic risk (APOE ε4) status. Vitamin D was associated with a significantly lower dementia incidence in females than males, for example.
Effects were also more significant in those with normal cognitive function (56% lower dementia incidence) versus those with mild cognitive impairment (33% lower incidence), the researchers reported. The latter finding “emphasizes the importance of interventions early in the disease course,” ideally before overt cognitive symptoms develop, the researchers wrote.
The results also showed that dementia gene carriers may benefit less from vitamin D supplementation than their peers without this genetic risk. Those at higher risk tend to store higher levels of vitamin D and so won’t have as notable a reaction to supplementation, the researchers said.
Supplement formulations
The findings were consistent across all vitamin D formulations studied: calcium–vitamin D, cholecalciferol and ergocalciferol, the authors reported.
Vitamin D supplements have the potential for preventing dementia, especially among people at high-risk for the disease, they concluded.
The study was published in Alzheimer’s & Dementia.
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