A randomized trial of Vitamin D supplementation on vascular function in CKD

Abstract

Vitamin D deficiency associates withmortality in patients with CKD, and Vitamin D supplementationmight mitigate cardiovascular disease risk in CKD. In this randomized, double-blind, placebo-controlled trial, we investigated the effect of cholecalciferol supplementation on vascular function in 120 patients of either sex, aged 18-70 years, with nondiabetic CKD stage 3-4 and Vitamin D deficiency (serum 25-hydroxyVitamin D ≤20 ng/ml). We randomized patients using a 1:1 ratio to receive either two directly observed oral doses of cholecalciferol (300,000 IU) or matching placebo at baseline and 8 weeks. The primary outcome was change in endothelium-dependent brachial artery flow-mediated dilation at 16 weeks. Secondary outcome measures included changes in pulse wave velocity and circulating biomarkers. Cholecalciferol supplementation significantly increased endothelium-dependent brachial artery flow-mediated dilation at 16 weeks, whereas placebo did not (between-group difference inmean change: 5.49%; 95% confidence interval, 4.34% to 6.64%; P<0.001). Intervention also led to significant favorable changes in pulse wave velocity and circulating IL-6 levels. Thus, in nondiabetic patients with stage 3-4 CKD and Vitamin D deficiency, Vitamin D supplementation may improve vascular function.