Coronary artery calcification (CAC) is a risk marker for CVD and mortality. In animal models, calcitriol significantly increased the serum calcium-phosphate product and aortic calcium content, while paricalcitol had no effect. The objective of this randomized, blinded single-center is to determine the differential effect of oral calcitriol and paracalcitol on vascular calcification in patients with chronic kidney disease (CKD).