JAMA : the journal of the American Medical Association
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Randomized Controlled Trial Comparative Study Clinical Trial
Blood pressure and metabolic effects of calcium supplementation in normotensive white and black men.
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. ⋯ 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.