Materials and methods. It is a prospective, randomised double-blind study carried out in parallel groups. 60 patients with CKD (GFR 15-60 ml/min) whose renal replacement therapy is to commence not earlier than in 9 months are planned to be qualified for the study. After familiarizing the patients with the aims of the study and obtaining their written consent, non-invasive tests will be carried out in order to estimate the presence and degree of vessel calcification: common carotid artery intima media thickness (CCA-IMT) by ultrasound examination, coronary artery calcium score (CACS) by multiscan CT as well as the presence of calcified heart valves by ultrasound examination. Patients with calcium score >10 (Agatston scoring system) will be qualified for the study. On the basis of randomised selection, patients will be divided into two groups: 30 patients will be given 90 μg vitamin K2+10 μg cholecalciferol (Vitamin D)and 30 patients will be given only 10 μg cholecalciferol. After a 9-month treatment the image diagnostic will be carried out in order to estimate the degree of vessel calcification. Patients and their basic laboratory test will be evaluated during the study period by a nephrologists on a monthly basis. First, at the commencement of the study, then after 3, 6 and finally after 9 months during the last visit, 10 ml of serum and plasma will be taken and frozen in order to conduct special marking tests: phosphorylated MGP (pMGP), uncarboxylated MGP (ucMGP), 25-OH cholecalciferol, hsCRP.