Cholecalciferol, Calcitriol, and Vascular Function in CKD: A Randomized, Double-Blind Trial

Background and objectives High circulating vitamin D levels are associated with lower cardiovascular mortality in CKD, possibly by modifying endothelial function. We examined the effect of calcitriol versus cholecalciferol supplementation on vascular endothelial function in patients with CKD. Design, setting, participants, & measurements We performed a prospective, double-blind, randomized trial of 128 adult patients with eGFR=15–44 ml/min per 1.73 m2and serum 25-hydroxyvitamin D level Results One hundred and fifteen patients completed the study. The mean (SD) age and eGFR of participants were 58±12 years old and 33.0±10.2 ml/min per 1.73 m2, respectively. There were no significant differences between groups at baseline. After 6 months, neither calcitriol nor cholecalciferol treatment resulted in a significant improvement in flow-mediated dilation (mean±SD percentage flow-mediated dilation; calcitriol: baseline 4.8±3.1%, end of study 5.1±3.6%; cholecalciferol: baseline 5.2±5.2%, end of study 4.7±3.6%); 25-hydroxyvitamin D levels increased significantly in the cholecalciferol group compared with the calcitriol group (cholecalciferol: 11.0±9.5 ng/ml; calcitriol: −0.8±4.8 ng/ml; P Conclusions Six months of therapy with calcitriol or cholecalciferol did not improve vascular endothelial function or improve inflammation in patients with CKD.