Vitamin K2 supplementation and arterial stiffness among renal transplant recipients-a single-arm, single-center clinical trial

J Am Soc Hypertens. 2017 Sep;11(9):589-597. doi: 10.1016/j.jash.2017.07.001. Epub 2017 Jul 13.


Subclinical vitamin K deficiency is prevalent among renal transplant recipients and is associated with an increased risk of cardiovascular disease. However, the association between vitamin K supplementation and improvement of arterial stiffness has not been explored in the renal transplant population. The KING trial (vitamin K2 In reNal Graft) is a single-arm study that evaluated the association between the change in vitamin K status and indices of arterial stiffness following 8 weeks of menaquinone-7 (vitamin K2) supplementation (360 μg once daily) among renal transplant recipients (n = 60). Arterial stiffness was measured using carotid-femoral pulse wave velocity (cfPWV). Subclinical vitamin K deficiency was defined as plasma concentration of dephosphorylated-uncarboxylated matrix Gla protein (dp-ucMGP) >500 pmol/L.At baseline, 53.3% of the study subjects had subclinical vitamin K deficiency. Supplementation was associated with a 14.2% reduction in mean cfPWV at 8 weeks (cfPWV pre-vitamin K2 = 9.8 ± 2.2 m/s vs. cfPWV post-vitamin K2 = 8.4 ± 1.5 m/s; P < .001). Mean dp-ucMGP concentrations were also significantly reduced by 55.1% following menaquinone-7 supplementation with a reduction in the prevalence of subclinical deficiency by 40% (P = .001). When controlled for age, durations of hemodialysis and transplantation, and the change in 24-hour mean arterial pressure, the improvement in arterial stiffness was independently associated with the reduction in dp-ucMGP concentration (P = .014).Among renal transplant recipients with stable graft function, vitamin K2 supplementation was associated with improvement in subclinical vitamin K deficiency and arterial stiffness. ( NCT02517580).

Keywords: Menaquinone; pulse wave velocity.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Biomarkers / blood
  • Calcium-Binding Proteins / blood
  • Dietary Supplements
  • Extracellular Matrix Proteins / blood
  • Female
  • Humans
  • Kidney Failure, Chronic / blood
  • Kidney Failure, Chronic / therapy*
  • Kidney Transplantation*
  • Male
  • Matrix Gla Protein
  • Middle Aged
  • Pilot Projects
  • Prevalence
  • Prospective Studies
  • Pulse Wave Analysis
  • Renal Dialysis
  • Treatment Outcome
  • Vascular Calcification / blood
  • Vascular Calcification / drug therapy
  • Vascular Calcification / epidemiology
  • Vascular Stiffness / drug effects*
  • Vitamin K / blood
  • Vitamin K 2 / therapeutic use*
  • Vitamin K Deficiency / blood
  • Vitamin K Deficiency / drug therapy*
  • Vitamin K Deficiency / epidemiology
  • Vitamins / therapeutic use*


  • Biomarkers
  • Calcium-Binding Proteins
  • Extracellular Matrix Proteins
  • Vitamins
  • Vitamin K 2
  • Vitamin K

Associated data