Vitamin D and nifedipine in the treatment of Chinese patients with grades I-II essential hypertension: a randomized placebo-controlled trial.

ABSTRACT

OBJECTIVES: Low vitamin D status has been shown to be associated with hypertension. We planned to research the effect of vitamin D and nifedipine in the treatment of patients with essential hypertension. METHODS: Patients with grades I-II essential hypertension were enrolled in this single-center, double-blind, placebo-controlled trial in Beijing. All patients received a conventional antihypertensive drug (nifedipine, 30 mg/d). One hundred and twenty-six patients were randomly assigned to receive vitamin D (n=63, 2000 IU/d) or a placebo (n=63) as an add-on to nifedipine, by the method of permutated block randomization. Ambulatory blood pressure monitoring was performed at baseline (month 0), at month 3 and at month 6. RESULTS: In vitamin D supplementation group, there was a significant increase in mean 25-hydroxyvitamin D levels from baseline (19.4 ± 11.6 ng/ml) to 6 months (34.1 ± 12.2 ng/ml; p<0.001). At 6 months, the primary end points, a difference in the fall of 24-h mean blood pressure, between the groups was -6.2 mmHg (95% CI -11.2; -1.1) for systolic blood pressure (p<0.001) and -4.2 mmHg (95% CI -8.8; -0.3) for diastolic blood pressure (p<0.001) under intention to treat analysis. In patients with vitamin D <30 ng/ml at baseline (n=113), 24-h mean blood pressure decreased by 7.1/5.7 mmHg (p<0.001). Safety and tolerability were similar among the two groups. CONCLUSIONS: Vitamin D supplementation can reduce blood pressure in patients with hypertension, it can be an adjuvant therapy for patients with grades I-II essential hypertension. CLINICAL TRIAL REGISTRATION This study was registered in the Chinese Clinical Trial Registry, it is available in Website http//www.chictr.org/cn/; REGISTRATION NUMBER ChiCTR-ONC-13003840.