Abstract: | ABSTRACT. There is epidemiologic evidence of a relationship between calcium deficiency and hypertension. The present study evaluated the effects of alphacalcidol, a synthetic analogue of active vitamin D, given to 29 patients with marginal, intermittent hypercalcaemia. Before therapy there was aninverse relationship between serum calcium levels and diastolic blood pressure (p<0.02). Treatment with 1 μg alphacalcidol raised the serum calcium by 0.07 mmol/l during a 6-month, double-blind, placebo-controlled trial and caused a significant reduction of diastolic blood pressure by 9.2 mmHg compared with placebo (p<0.01). The study extends previous observations, in normocalcaemic subjects, of inverse relationships between serum calcium and blood pressure indicating a primary disturbance of calcium homeostasis in hypertension. The observation that a physiologic amount of active vitamin D has hypotensive effects agrees with such a concept and suggests a new principle for the treatment of hypertension. |