Vitamin D supplementation can improve endothelial dysfunction in patient with non-dialysis chronic kidney disease (CKD), new study findings suggest.
A team from the Medical School of Nanjing University in China tested treatment with oral cholecalciferol at 50,000 units per week for 12 weeks in 71 patients with non-dialysis CKD and serum levels of 25-hydroxyvitamin D (25(OH)D) below 30 ng/mL. According to findings published in International Urology and Nephrology, mean serum levels of 25(OH)D increased significantly from 13.2 ng/mL at baseline to 33.7 ng/mL after supplementation. Results showed that 35.2% of patients did not achieve normal serum 25(OH)D levels, and multivariable analysis showed that these patients tended to have higher proteinuria and lower levels of 25(OH)D at baseline. Intact parathyroid hormone levels decreased slightly from 96.14 to 91.2 pg/mL.
The investigators observed statistically significant improvement in endothelial function. Brachial artery flow-mediated dilation (FMD), measured by high-resolution ultrasound, increased significantly from 4.4% to 5.1%. Soluble endothelial biomarkers decreased significantly. Soluble vascular cell adhesion molecule-1 (sVCAM-1) levels fell from 926.9 to 867.0 ng/mL and sE-selectin levels declined from 69.7 to 63.3 ng/mL.
“Our results indicated that supplemental 25(OH)D is associated with increased brachial artery FMD and decreased levels of sVCAM-1 and sE-selectin, two important markers of endothelial activation that play an important role in the development of atherosclerosis,” senior author Chunming Jiang, MD, and his colleagues explained. “Thus, it is possible that vitamin D supplementation may reduce cardiovascular events through improving endothelial dysfunction in CKD patients.”
The results extend findings from a 2014 study published in PLoS ONE, which found improved endothelial function with vitamin D supplementation in patients with stage 3 to 4 CKD.
Dr Jiang and his team pointed out some study limitations. Many participants were receiving renin-angiotensin-system inhibitors, statins, and aspirin, which might have affected endothelial function, although none of the drug therapies changed during the study. In addition, the study demonstrated statistical improvement, but “the clinical importance may be modest, since all of these markers were still far from the normal range.”
Zhang Q, Zhang M, Wang H, et al. Vitamin D supplementation improves endothelial dysfunction in patients with non‑dialysis chronic kidney disease. Intl Urol Nephrol. doi:10.1007/s11255-018-1829-6