Lifestyle and nutritional factors influence the risk of dementia, particularly among people with prediabetes – a condition characterized by elevated blood sugar levels that are not high enough to be classified as diabetes. A recent study found that higher vitamin D levels may reduce the risk of developing dementia in older adults with prediabetes.

Researchers drew on data collected from a large cohort of more than 34,000 older adults enrolled in the UK Biobank, all of whom had prediabetes but did not have dementia at the start of the study. They measured the participants' blood vitamin D levels and monitored them for the development of dementia, including Alzheimer’s disease and vascular dementia, for approximately 12 years. Their analysis also considered genetic variations that could influence the relationship between vitamin D levels and dementia risk.

They found that participants with higher blood vitamin D levels were 18 percent less likely to develop any type of dementia, with similar findings for Alzheimer’s disease and vascular dementia. The protective effect of vitamin D was particularly robust in participants who did not carry polymorphisms (genetic variants) related to the vitamin D receptor, highlighting a potential interaction between genetics and vitamin D levels in dementia risk.

These findings suggest that maintaining adequate levels of vitamin D benefits brain health, especially in older adults with prediabetes, a group at elevated risk for dementia. They add to the growing body of evidence supporting the importance of vitamin D for overall health and emphasize the need for further research to understand the mechanisms behind its protective effects on the brain. Learn more about vitamin D in our comprehensive overview article.