Low-dose menaquinone-7 supplementation improved extra-hepatic vitamin K status, but had no effect on thrombin generation in healthy subjects

Theuwissen E, Cranenburg EC, Knapen MH, et al. · British Journal of Nutrition

The dose-ranging study that brackets a 200 ug capsule: MK-7 at doses around the recommended daily allowance increased carboxylation of both circulating osteocalcin and matrix Gla protein, while doses below it did not reliably do so, and thrombin generation was unaffected at every dose.

Population

Healthy Dutch men and women aged 18-45, randomised to seven groups

Intervention

MK-7 at 10, 20, 45, 90, 180 or 360 ug/day

Comparator

Placebo

Limitations

Six per dose group, so the analysis had to collapse the seven arms into three to reach any statistical power; young healthy adults over a short period; carboxylation markers, not clinical outcomes.