Racial Disparity in Blood Pressure: is Vitamin D a Factor?
- 220 Downloads
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
- 1.Fryar CD, Hirsch R, Eberhardt MS, Yoon SS, Wright JD. Hypertension, High Serum Total Choleseterol, and Diabetes: Racial and Ethnic Prevalence Differences in U.S. Adults, 1999–2006. Hyattsville, MD: National Center for Health Statistics, 2010.Google Scholar
- 12.Pilz S, Tomaschitz A, Ritz E. Pieber TR. Medscape. Vitamin D status and arterial hypertension: a systematic review. Nature Rev Cardiol. 2009;6:621–630.Google Scholar
- 15.Signorello LB, Williams SM, Zheng W et al. Blood vitamin D levels in relation to genetic estimation of African ancestry. Cancer Epidemiol Biomarkers Prev. 2010.Google Scholar
- 20.National Health and Nutrition Examination Survey. National Health and Nutrition Examination Survey. Physician examination procedures manual (original 1999, revised 2000). http://www.cdc.gov/nchs/data/nhanes/nhanes_01_02/physician_year_3.pdf acccessed 3/18/2011.
- 25.Ham SA, Ainsworth BE. Disparities in data on Healthy People 2010 physical activity objectives collected by accelerometry and self-report. Am J Public Health. 2010;100:Suppl-8.Google Scholar
- 31.Jamerson KA. The disproportionate impact of hypertensive cardiovascular disease in African Americans: getting to the heart of the issue. J Clin Hypertens. 2004;6:Suppl-10.Google Scholar
- 59.Wilson TW, Hollifield LR, Grim CE. Systolic blood pressure levels in black populations in sub-Sahara Africa, the West Indies, and the United States: a meta-analysis. Hypertension. 1991;18:Suppl-91.Google Scholar