Vitamin D may protect against stroke

February 13, 2012

New US research suggests that consuming sufficient amounts of vitamin D may protect against incident strokes and cognitive impairment.

In the ‘Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study’, 26,039 black and white participants aged 45 years and older were surveyed every 6 months for strokes and assessed for cognitive function annually for a mean of 5 years (1). In addition, vitamin D consumption was measured using a food-frequency questionnaire. The study results showed that vitamin D from both supplements and food was associated with a lower risk for stroke and cognitive decline: participants with higher levels of vitamin D had an associated 11% reduction in stroke and 24% reduction in cognitive impairment versus those with lower levels, after the researchers adjusted for age, race, income, education, hypertension, diabetes, high cholesterol, history of cardiovascular disease and weight. Higher vitamin D intake was more common among white participants as compared with black participants, but did not differ by age or sex.

According to the researchers, one limitation of the study is that there had been no good measure of vitamin D from sun exposure. Blood levels of vitamin D may be a better marker to account for diet and sun exposure. The scientists recommended examining the role of vitamin D in preserving brain function and determining the optimum dose that to improve outcomes.


  1. Judd S. E. Abstract No. 2212. Presented at: the American Stroke Association’s International Stroke Conference 2012. New Orleans, USA. February 2012.