Background: As cardiovascular factors are the leading cause of mortality in chronic kidney disease (CKD) and as vitamin D deficiency is prevalent in this population, we aimed to examine the effect of oral cholecalciferol on cardiac parameters and biomarkers for endothelial cell activation in children with CKD.

Methods: Forty-one children with CKD and 24 healthy subjects free of any underlying cardiac or renal disease with low 25-hydroxyvitamin D3 (25OHD) levels were evaluated using echocardiography basally and following Stoss vitamin D supplementation. The local vascular stiffness and endothelial dysfunction markers were compared among the groups.

Results: Initial flow-mediated dilatation (FMD) measurements were lower and local arterial stiffness was significantly higher in patients. After vitamin D supplementation, these improved significantly in patients, while no significant change was observed for the healthy group. Homocysteine showed inverse correlation with baseline vitamin D level in CKD children and von Willebrand factor emerged as an independent risk factor for FMD impairment.

Conclusions: Our interventional study revealed the favorable effects of high-dose cholecalciferol on cardiovascular and endothelial parameters, implying the importance of vitamin D supplementation in children with CKD.