Vit D Supplements May Reduce Blood Pressure in Blacks
New research at the Brigham and Women’s Hospital’s Kidney Clinical Research Institute in Boston suggests that vitamin D supplementation may modestly lower blood pressure among black adults. Studies show that blacks have higher rates of hypertension (high blood pressure) than whites in the U.S. They also have lower circulating levels of vitamin D or 25(OH)D.
John P. Forman, MD, MSc, and colleagues conducted a clinical trial involving an 250 black participants who were randomly assigned to receive either placebo or one of three doses of vitamin D3 (or cholecalciferol at 1,000, 2,000 or 4,000 IU daily). Treatment was started in early winter to control sunlight-derived vitamin D.
The results, which were recently published in the journal Hypertension, showed that after three months of treatment, serum vitamin D levels increased in a dose-dependent manner and declined after the end of the study at 6 months, although they remained higher than baseline. Participants who received placebo had an increase in systolic blood pressure (SBP) by 1.7 mm Hg, while those who received vitamin D supplements saw a dose-dependent decline in SBP. The authors believe that the 0.2-mmHg greater reduction in SBP per 1-ng/mL in vitamin D levels is significant, and supports a true causal association between serum vitamin D levels and blood pressure. However, they also note that larger, longer studies are needed to confirm the effect.
The investigators believe that if proven, vitamin D supplementation could be a good way to prevent or reduce blood pressure among blacks, who have higher prevalence of hypertension and lower vitamin D levels than whites. They explain that vitamin D works to reduce blood pressure by regulating the renin-angiotensin system, which is believed to be a stronger mediator of blood pressure among blacks.
Phend, C. Vitamin D May Pare BP for Blacks. MedPage Today.