SUNDAY, Nov. 14 (HealthDay News) -- New research suggests that
vitamin D deficiency does not boost stroke death rates among black
patients, even though it appears to double the risk for whites.
The authors expressed some surprise at the findings, given that
prior research has revealed that blacks are overall more prone to
vitamin D deficiency and more likely to experience a stroke,
compared with white patients. Blacks also have a 60 percent higher
risk of dying from a stroke than whites, they added.
"We thought maybe the lower vitamin D levels might actually explain why blacks have higher risks for stroke," study author Dr. Erin Michos, an assistant professor of medicine at Johns Hopkins University School of Medicine in Baltimore, said in a news release from the American Heart Association. "But we did not find the same relationship between vitamin D and stroke in blacks."
Michos and his colleagues are slated to present their findings
Monday at the American Heart Association annual meeting in
Stroke is the third most common cause of death in the United
States, the authors noted.
Their analysis stems from a review of health records of
approximately 8,000 adults obtained from the Third National Health
and Nutrition Examination Survey of Americans (NHANES-III)
conducted between 1988 and 1994.
Almost 7 percent of the white patients were vitamin D-deficient,
compared with more than 32 percent of the black participants.
Whites with too little Vitamin D had twice the risk of dying from
stroke as whites with adequate levels of the vitamin, which is
obtained from fortified dairy products, fatty fish and exposure to
The findings held up even after accounting for a host of
socioeconomic and stroke risk factors, such as a history of
diabetes, high blood pressure, cholesterol, body-mass index,
smoking, physical activity and/or alcohol use.
Blacks could have a natural resistance to the negative effects
of vitamin D deficiency, Michos said. This could explain why blacks
have fewer bone fractures than whites, despite the higher incidence
of low vitamin D levels, Michos added.
For more on vitamin D, visit the
U.S. National Institutes of Health.