[Intestinal calcium and vitamin D absorption in essential arterial hypertension]

The intestinal absorption of calcium and seric levels of calcifediol and calcitriol were studied in 27 patients with essential blood hypertension (BH) and 20 normal patients in a control group. The hypertensive patients were divided in three groups depending on the plasmatic renin activity (PRA), (high, normal, low). We found a significantly higher rate of intestinal calcium absorption in the group of patients with BH and low PRA than in the control group (22.73 +/- 19.05 and 10.7 +/- 17.13% respectively) (p less than 0.025). The seric levels of calcitriol (1,25 (OH) 2D3) were significantly higher in the group of patients with hypertension and low PRA than in the control group (48.16 +/- 5.25 and 33.13 +/- 2.9 pg/ml respectively) (p less than 0.025). The seric levels of calcifediol (25-OH-D3) were significantly lower in low PRA patients than those patients in the control group (12.37 +/- 2.44 and 21.94 +/- 2.82 ng/ml respectively) (p less than 0.025). We concluded that patients with essential blood hypertension and low PRA have significantly lower calcitriol levels than any other group, probably conditioning the greater intestinal calcium absorption shown in this group.