Epidemiological studies have consistently linked low 25-hydroxyvitamin D (25OHD) to higher risk of hypertension.1 The few small randomized controlled trials (RCTs) of vitamin D and blood pressure have yielded inconclusive results but tend to support a modest reduction in blood pressure.2 Given the importance of hypertension as a cardiovascular risk factor, the identification of nontoxic, inexpensive interventions remains important. In this light, RCTs on the role of vitamin D on blood pressure, such as the one by Witham et al3 reported in this issue of JAMA Internal Medicine, are critical. Briefly, this study selected patients 70 years and older with isolated systolic hypertension and a baseline 25OHD level of less than 30 ng/mL (to convert to nanomoles per liter, multiply by 2.496). The RCT consisted of 100 000 IU of oral cholecalciferol or matching placebo every 3 months for 1 year. The results were disappointing because no appreciable change in blood pressure was found. These findings may dampen some of the enthusiasm for vitamin D as a powerful agent in uniformly lowering blood pressure. However, it is important to put this study in context of other evidence.
Giovannucci E. Cholecalciferol Treatment in Older Patients With Isolated Systolic Hypertension. JAMA Intern Med. 2013;173(18):1680-1681. doi:10.1001/jamainternmed.2013.8019