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

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Endocrinology

Background:

• High vitamin D levels correlate with reduced cardiovascular mortality in chronic kidney disease (CKD).
• Vitamin D may influence endothelial function, a key factor in cardiovascular health.
• The specific effects of different vitamin D analogs on vascular health in CKD remain under investigation.

Purpose of the Study:

• To compare the effects of calcitriol and cholecalciferol supplementation on vascular endothelial function in CKD patients.
• To assess changes in brachial artery flow-mediated dilation as a primary outcome.
• To evaluate the impact on markers of mineral metabolism and inflammation.

Main Methods:

• A prospective, double-blind, randomized trial involving 128 adult CKD patients (eGFR 15-44 ml/min/1.73 m²).
• Participants received either oral cholecalciferol (2000 IU daily) or calcitriol (0.5 μg daily) for six months.
• Flow-mediated dilation was measured, alongside secondary endpoints including mineral metabolism and inflammation markers.

Main Results:

• 115 patients completed the study; no significant baseline differences were observed.
• Neither calcitriol nor cholecalciferol significantly improved flow-mediated dilation after six months.
• Cholecalciferol increased 25-hydroxyvitamin D levels more than calcitriol, while calcitriol significantly reduced parathyroid hormone levels.

Conclusions:

• Six months of calcitriol or cholecalciferol therapy did not enhance vascular endothelial function in CKD patients.
• Neither vitamin D analog demonstrated an improvement in inflammation markers.
• Further research may be needed to explore other therapeutic strategies for vascular health in CKD.