MO789: The Effect of Oral Vitamin K2 Versus K1 on Vascular Calcification in Hemodialysis Patients: A Randomized Controlled Trial

Abstract BACKGROUND AND AIMS Vascular calcification is a common complication of end-stage renal disease and an important cause of cardiovascular diseases and mortality. Vitamin K is essential for the activation of matrix Gla protein (MGP), a powerful inhibitor of tissue calcification. However, there are limited data on the efficacy and safety of different vitamin K forms on vascular calcification in hemodialysis patients, most of whom are essentially vitamin K deficient. METHOD A prospective, randomized, placebo-controlled clinical trial, that included 120 eligible hemodialysis patients who were randomly assigned to one of three equal study groups: vitamin K1 (10 mg phytomenadione thrice-weekly), vitamin K2 (90 ug daily), or placebo for 3 months. Serum MGP, calcium, phosphorus, their product and intact parathyroid hormone (iPTH) levels were all assessed at baseline and at the end of the study. RESULTS MGP levels showed a significant increase in the vitamin K2 group (700%) compared with (78%) and (40%) in vitamin K1 and placebo groups respectively. No change was found in bone profile at 3 months compared with baseline at both of the treatment groups. No correlations between calcium, phosphorous and PTH and MGP levels at baseline or after treatment. None of the treatment group patients experienced any adverse effects. CONCLUSION Vitamin K supplementation was tolerable and effective in improving levels of a potent calcification inhibitor as MGP, with K2 form showing superiority over K1 in their impact on MGP levels among hemodialysis patients.