The role of vitamin K in vascular calcification of patients with chronic kidney disease.

Patients with chronic kidney disease (CKD) are prone to vascular calcification. Pathogenetic mechanisms of vascular calcifications have been broadly studied and discussed such as the role of hyperphosphatemia, hypercalcemia, parathormone, and vitamin D. In recent years, new insights have been gained pointing to vitamin K as a main actor. It has been discovered that vitamin K is an essential cofactor for the activation of matrix Gla protein (MGP), a calcification inhibitor in the vessel wall. Patients with CKD often suffer from vitamin K deficiency, resulting in low active MGP and eventually a lack of inhibition of vascular calcification. Vitamin K supplementation and switching warfarin to new oral anticoagulants are potential treatments. In addition, MGP may have a role as a non-invasive biomarker for vascular calcification.