Can vitamin K2 reduce arterial stiffness?

What does the research say?

Using the same group of women as the bone study, researchers found that three years of vitamin K2 (MK-7) improved measures of arterial stiffness, particularly in women whose arteries were stiffest at the start. Stiffer arteries are linked with higher cardiovascular risk.

The science

Vitamin K activates matrix Gla protein (MGP), which helps prevent calcium building up in artery walls. Low vitamin K status is associated with higher levels of inactive MGP and stiffer arteries.

In this trial, MK-7 roughly halved levels of inactive MGP and improved stiffness measures (the stiffness index β, and pulse wave velocity in women with above-average stiffness), while arteries in the placebo group continued to stiffen with age.

Key findings

• Inactive MGP fell by about half with MK-7.
• Arterial stiffness improved in the MK-7 group, especially in women with stiffer arteries at the start.
• Arterial stiffness continued to increase in the placebo group.

Limitations

• Arterial stiffness is a risk marker, not a heart attack or stroke outcome.
• Only healthy postmenopausal women were studied.
• Stiffness measures were a secondary focus of the trial.
• Not suitable for people on warfarin or other vitamin K antagonists without medical advice.

References

1. Knapen MHJ, Braam LAJLM, Drummen NE, Bekers O, Hoeks APG, Vermeer C. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women: a double-blind randomised clinical trial. Thromb Haemost. 2015;113(5):1135–1144. doi.org/10.1160/TH14-08-0675