Vitamin D is a steroid hormone that plays critical roles in many physiological processes, including blood pressure regulation, immune function, and cell growth. Findings from a new study suggest that vitamin D prevents dementia. People who took vitamin D were 40 percent less likely to develop dementia than those who didn’t.

The study involved more than 12,000 older adults who did not have dementia at enrollment. Researchers categorized the participants based on their vitamin D exposure: those exposed to vitamin D before dementia onset and those not exposed before dementia onset. They also examined different forms of vitamin D (calcium + vitamin D, cholecalciferol [D3], and ergocalciferol [D2]) to see if their effects on dementia rates varied and explored potential interactions with other risk factors for dementia, such as age, sex, education, race, cognitive function, depression, and apolipoprotein E4 (APOE4) status.

They found that participants exposed to vitamin D had a 40 percent lower risk of developing dementia. They were also dementia-free longer than those without vitamin D exposure. These effects were evident across various forms of vitamin D. Further analysis revealed that sex, cognitive status, and APOE4 status influenced the extent of vitamin D’s effects on dementia risk. For example, females, people with normal cognitive function, and those who did not carry the APOE4 gene variant seemed to gain greater protection against dementia.

These findings suggest that vitamin D supplementation holds promise as a preventive measure for dementia, especially for people at higher risk of developing the condition. However, more research is required to fully understand the mechanisms behind this association and establish specific vitamin D supplementation guidelines to reduce dementia risk. Learn more about vitamin D in our comprehensive overview article.

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