Table 1.

Interventional clinical trials regarding the effects of vitamin K2 (MK-7) supplementation on circulating forms of MGP and arterial calcification and stiffness.

Study design, population, year, reference	Intervention	Study duration	Result
Single-arm, clinical, 17 HD patients, 2011, (51)	135 μg/day MK-7	6 weeks	27% ↓ of dp-ucMGP No effect on dpcMGP
Randomized, non-placebo controlled, clinical, 53 HD patients, 2012, (60)	45, 135, or 360 μg/day MK-7 in three groups, respectively	6 weeks	45 μg group: 17.9% ↓ of dp-ucMGP 135 μg group: 36.7% ↓ of dp-ucMGP 360 μg group: 61.1% ↓ of dp-ucMGP
Prospective, randomized, single-blinded, clinical, 200 HD patients, 2014, (28)	360, 720, or 1080 μg/thrice weekly MK-7 in three groups, respectively	8 weeks	360 μg group: 17% ↓ of dp-ucMGP 720 μg group: 33% ↓ of dp-ucMGP 1080, μg group: 46% ↓ of dp-ucMGP
Randomized, double-blind, clinical, 40 non-dialyzed CKD patients stage 3–5, 2015, (66)	10 μg/day vitamin D+ 90 μg/day MK-7 or 10 μg/day vitamin D	9 weeks	D group: ↑ of dp-ucMGP, ↓ of MGP MK-7+D group: ↓ of dp-ucMGP, ↑ of MGP, slower progression of vascular calcification compared to the vitamin D group
Pre-post, clinical, 50 HD patients, 2017, (67)	360 μg/day MK-7	4 weeks	↓ 86% of dp-ucMGP
Single-arm, single-center, clinical, 60 kidney transplant recipients, 2017, (68)	360 μg/day MK-7	8 weeks	55.1% ↓ of dp-ucMGP 14.2% ↓ of arterial stiffness 40% ↓ of the prevalence of subclinical vitamin K deficiency

MK-7, menaquinone 7; MGP, Matrix Gla Protein; Dp-ucMGP, dephosphorylated, uncarboxylated MGP; D-pcMGP, dephosphorylated, carboxylated MGP; HD, hemodialysis; CKD, chronic kidney disease.