The effect of vitamin D supplementation on blood pressure in patients with elevated blood pressure and vitamin D deficiency: a randomized, double-blind, placebo-controlled trial.

OBJECTIVES The present evidence indicates a reverse correlation between vitamin D status and blood pressure (BP). The present study determined the effect of oral vitamin D supplementation on BP in patients with elevated BP and vitamin D deficiency. MATERIALS AND METHODS In this randomized, double-blind, placebo-controlled trial, 42 outpatients with elevated BP and vitamin D deficiency were assigned randomly to two groups: the vitamin D-supplemented group (VDG), who received one capsule containing 50 000 IU of cholecalciferol weekly, and the placebo group (PG), who received one similar capsule containing oral liquid paraffin as placebo for 8 weeks. The systolic (SBP) and diastolic (DBP) blood pressures, mean arterial blood pressure (MAP), pulse pressure, serum 25-hydroxyvitamin D, parathormone, calcium, phosphorus, magnesium, sodium, and potassium were measured before and after the intervention. RESULTS In all, 92.7% of the VDG recovered from vitamin D deficiency. At the end of the intervention, the mean SBP and DBP, and the MAP decreased significantly in VDG compared with the PG, whereas at the beginning of the intervention, there was no significant difference between the two groups. The mean changes in SBP (-6.4±5.3 vs. 0.9±3.7 mmHg, P(V)<0.001), DBP (-2.4±3.7 vs. 1.0±2.7 mmHg, P(V)=0.003), and MAP (-3.7±3.6 vs. 0.9±2.5 mmHg, P(V)<0.001) were lower in the VDG than PG. CONCLUSION The findings of the study showed that the weekly administration of 50 000 IU of oral vitamin D for 8 weeks as an adjunct supplement of antihypertensive drugs in patients with vitamin D deficiency could help prevent vitamin D deficiency and aid control of SBP, DBP, and MAP.