Background: Vascular calcification is a common complication of end stage renal disease patients, an important cause of cardiovascular disease and all-cause mortality. Vitamin K is essential for the activation of matrix Gla protein (MGP), a powerful inhibitor of tissue calcification. Different forms of vitamin K have been proposed to have a good impact on vascular calcification. However, clinical data are still limited on efficacy and safety of different forms of vitamin K.

Methods : A prospective, randomized, placebo-controlled study that included 120 eligible hemodialysis patients who were randomly assigned to either vitamin k1 group (10 mg phytomenadione thrice weekly) or vitamin k2 group (90 ug daily) or placebo group 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: There were significant increase in percentages of change in MGP levels in Vitamin k2 group (700%) compared to (78%) in Vitamin k1 & (40%) in placebo groups. No correlations observed 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 with k2 form showing superiority over k1 in their impact on MGP levels among hemodialysis patients.

ClinicalTrials.gov registration number: NCT04477811.