Racial Disparity in Blood Pressure: is Vitamin D a Factor?
Higher prevalence of hypertension among African Americans is a key cause of racial disparity in cardiovascular morbidity and mortality. Explanations for the difference in prevalence are incomplete. Emerging data suggest that low vitamin D levels may contribute.
To assess the contribution of vitamin D to racial disparity in blood pressure.
Adult non-Hispanic Black and White participants from the National Health and Nutrition Examination Survey 2001–2006.
We assessed Black-White differences in systolic blood pressure (SBP) controlling for conventional risk factors, and then additionally, for vitamin D (serum 25[OH]D).
The sample included 1984 and 5156 Black and White participants ages 20 years and older. The mean age-sex adjusted Black-White SBP difference was 5.2 mm Hg. This difference was reduced to 4.0 mm Hg with additional adjustment for socio-demographic characteristics, health status, health care, health behaviors, and biomarkers; adding 25(OH)D reduced the race difference by 26% (95% CI 7–46%) to 2.9 mm Hg. This effect increased to 39% (95% CI 14–65%) when those on antihypertensive medications were excluded. Supplementary analyses that controlled for cardiovascular fitness, percent body fat, physical activity monitoring, skin type and social support yielded consistent results.
In cross-sectional analyses, 25(OH)D explains one quarter of the Black-White disparity in SBP. Randomized controlled trials are required to determine whether vitamin D supplementation could reduce racial disparity in BP.
KEY WORDSvitamin D blood pressure African continental ancestry
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