EFFECT OF CALCIUM SUPPLEMENTATION ON DIASTOLIC BLOOD PRESSURE IN YOUNG PEOPLE WITH MILD HYPERTENSION

Abstract

In a double-blind trial 90 mildly hypertensive subjects aged 16-29 years were randomly assigned to 1 g calcium per day or placebo. Calcium supplementation did not affect systolic blood pressure, but at six and twelve weeks diastolic blood pressure had fallen by 3·1 (p = 0·04) and 2·4 (p = 0·11) mm Hg, respectively, more in the calcium group than it had in the placebo group. Subjects with a baseline plasma parathyroid hormone (PTH) higher than the median showed a 6·1 mm Hg (p = 0·01) greater fall in diastolic blood pressure after six weeks and 5·4 mm Hg (p = 0·01) after twelve than in the placebo group. The fall in diastolic blood pressure was greater in the calcium group than in the placebo group in subjects with a lower than median serum total calcium and in those with a large bodyweight. Calcium supplementation may lower blood pressure in young people with mildly raised blood pressure, particularly in those with high plasma PTH and/or low serum total calcium.