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

Eelderink C, Kremer D, Riphagen IJ, et al. · American Journal of Transplantation

Supplementing people who were genuinely deficient: calcification propensity did not change, but pulse wave velocity held steady on MK-7 (-0.06 m/s) while it worsened on placebo (+0.27 m/s, P=0.010), and inactive matrix Gla protein fell by 385 pmol/L — although most participants were still deficient at the end.

Population

Kidney transplant recipients with documented vitamin K deficiency (dp-ucMGP at or above 500 pmol/L), 12 weeks

Intervention

MK-7 360 ug/day

Comparator

Placebo

Limitations

Forty participants at one centre for 12 weeks; arterial stiffness was a secondary endpoint and the primary endpoint was null; a transplant population with distinctive vascular biology.