Effect of vitamin K supplementation on serum calcification propensity and arterial stiffness in vitamin K-deficient kidney transplant recipients: A double-blind, randomized, placebo-controlled clinical trial

C. Eelderink, D. Kremer*, I.J. Riphagen, T.J. Knobbe, L.J. Schurgers, A. Pasch, D.J. Mulder, E. Corpeleijn, G. Navis, S.J.L. Bakker, M.H.D. Borst, C.A.T. Velde-Keyzer

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Vitamin K deficiency is common among kidney transplant recipients (KTRs) and likely contributes to progressive vascular calcification and stiffness. In this single-center, randomized, double-blind, placebo-controlled trial, we aimed to investigate the effects of vitamin K supplementation on the primary end point, serum calcification propensity (calciprotein particle maturation time, T50), and secondary end points arterial stiffness (pulse wave velocity [PWV]) and vitamin K status in 40 vitamin K-deficient KTRs (plasma dephosphorylated uncarboxylated matrix Gla protein [dp-ucMGP] >= 500 pmol/L). Participants (35% female; age, 57 +/- 13 years) were randomized 1:1 to vitamin K2 (menaquinone-7, 360 mu g/day) or placebo for 12 weeks. Vitamin K supplementation had no effect on calcification propensity (change in T50 vs baseline +2.3 +/- 27.4 minutes) compared with placebo (+0.8 +/- 34.4 minutes; Pbetween group = .88) but prevented progression of PWV (change vs baseline-0.06 +/- 0.26 m/s) compared with placebo (+0.27 +/- 0.43 m/s; Pbetween group = .010). Vitamin K supplementation strongly improved vitamin K status (change in dp-ucMGP vs baseline-385 [-631 to-269] pmol/L) compared with placebo (+39 [-188 to +183] pmol/L; Pbetween group < .001), although most patients remained vitamin K-deficient. In conclusion, vitamin K supplementation did not alter serum calcification propensity but prevented progression of arterial stiffness, suggesting that vitamin K has vascular effects independent of calciprotein particles. These results set the stage for longer-term intervention studies with vitamin K supplementation in KTRs.Trial registry: EU Clinical Trials Register (EudraCT Number: 2019-004906-88) and the Dutch Trial Register (NTR number: NL7687).
Original languageEnglish
Pages (from-to)520-530
Number of pages11
JournalAmerican Journal of Transplantation
Issue number4
Publication statusPublished - 1 Apr 2023


  • clinical research
  • practice
  • kidney transplantation
  • nephrology
  • nutrition
  • vascular biology
  • cardiovascular disease
  • vascular health
  • arterial stiffness
  • calcification propensity
  • vitamin K

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