A Randomized Trial of Vitamin D Supplementation on Vascular Function in CKD

Area of Science:

• Nephrology
• Endocrinology
• Cardiovascular Medicine

Background:

• Vitamin D deficiency is linked to increased mortality in chronic kidney disease (CKD) patients.
• Vitamin D supplementation may reduce cardiovascular disease (CVD) risk in CKD.
• Vascular dysfunction is a significant concern in patients with CKD.

Purpose of the Study:

• To investigate the effect of cholecalciferol supplementation on vascular function in patients with nondiabetic CKD stages 3-4 and vitamin D deficiency.
• To assess changes in endothelium-dependent brachial artery flow-mediated dilation (FMD) as the primary outcome.

Main Methods:

• A randomized, double-blind, placebo-controlled trial involving 120 patients (aged 18-70) with nondiabetic CKD stages 3-4 and vitamin D deficiency (serum 25-hydroxyvitamin D ≤20 ng/ml).
• Patients received two oral doses of cholecalciferol (300,000 IU) or placebo at baseline and 8 weeks (1:1 ratio).
• Primary outcome: change in brachial artery FMD at 16 weeks. Secondary outcomes: pulse wave velocity and circulating biomarkers.

Main Results:

• Cholecalciferol supplementation significantly increased FMD at 16 weeks compared to placebo (mean change difference: 5.49%; P<0.001).
• The intervention group showed significant favorable changes in pulse wave velocity.
• Circulating interleukin-6 (IL-6) levels were also favorably affected by cholecalciferol supplementation.

Conclusions:

• Vitamin D supplementation with cholecalciferol may improve vascular function in nondiabetic patients with stage 3-4 CKD and vitamin D deficiency.
• The findings suggest a potential role for vitamin D in mitigating cardiovascular risk in this patient population.
• Further research is warranted to confirm these vascular benefits and their long-term clinical implications.