Blood pressure and metabolic effects of calcium supplementation in normotensive white and black men

Abstract

A randomized, double-blind, placebo-controlled trial was conducted to examine the effect of calcium supplementation on blood pressure in normotensive black (n = 21) and white (n = 54) men, aged 19 to 52 years. After a four-week baseline period of weekly blood pressure measurement, subjects were randomly assigned within racial groups to either a treatment (calcium, 1500 mg/d) or placebo group for a 12-week period. During the experimental period, multiple blood pressure measurements were taken every two weeks in both the seated and supine positions, using a random baseline sphygmomanometer. A repeated-measures analysis of covariance yielded a modest but significantly lower seated mean arterial pressure in the treatment group compared with the control group, but no differences between the races. Results were similar for supine blood pressure. Calcium supplementation, in comparison with placebo, resulted in lower mean arterial pressure in normotensive white and black men during a 12-week period. The overall blood pressure-lowering effect was not correlated with the response of serum levels of total and ionized calcium, total inorganic phosphorus, or parathyroid hormone, or overnight urinary electrolyte values.