What did the 2026 vitamin K2 study find?

In a two-year randomized, placebo-controlled trial of 180 adults with existing coronary artery disease, those taking 360 micrograms of vitamin K2 (MK-7) daily had about 29% less progression of coronary artery calcification than those taking a placebo.

Does vitamin K2 prevent heart attacks?

That has not been established. The study measured calcium buildup in the arteries, not heart attacks or other cardiovascular events, so researchers do not yet know whether slowing calcification with K2 reduces those events.

Is vitamin K2 safe for everyone?

Vitamin K2 has a strong safety record in research, but people taking warfarin or similar vitamin K-antagonist medications should not take it without medical guidance, because vitamin K can interfere with how those medications work. Always check with your own medical provider before starting a supplement.

Can Vitamin K2 Help Slow Calcium Buildup in Your Arteries?

Q: What is the difference between MK-4 and MK-7?

They are two forms of vitamin K2. Many osteoporosis studies used MK-4, often at relatively high doses, while much of the recent cardiovascular research, including this trial, used MK-7.

New research offers encouraging evidence for cardiovascular health.

Vitamin K2 softgels in a heart-shaped bowl beside natto, aged cheese and egg yolks

We often think of calcium as an essential mineral for strong bones and teeth. But calcium can also accumulate where we don't want it, including our arteries. Coronary artery calcification is associated with an increased risk of cardiovascular disease.

An intriguing study published in JAMA Cardiology in 2026 suggests that vitamin K2 may help slow this process.

What Did the Researchers Discover?

In this randomized, double-blind, placebo-controlled study, researchers assigned 180 adults with existing coronary artery disease to receive either 360 micrograms of vitamin K2 (MK-7) or a placebo daily for two years. Using specialized CT scans, researchers measured changes in calcium accumulation within the coronary arteries.

The results were encouraging: participants receiving vitamin K2 experienced approximately 29% less progression of coronary artery calcification compared with those receiving a placebo. The difference was statistically significant.

Notably, participants already had coronary artery disease, and many were taking statins or had a history of smoking—factors associated with changes in coronary calcification. The study also used vitamin K2 alone, without additional vitamin D3, raising questions about whether the benefits might differ in lower-risk individuals or when the two vitamins are combined.

Why Might Vitamin K2 Make a Difference?

Vitamin K2 helps activate matrix Gla protein (MGP), which plays an important role in regulating calcium deposition in blood vessels. Without sufficient vitamin K activity, MGP cannot function optimally.

K2 also activates osteocalcin, a protein involved in bone mineralization. This connection between bone and cardiovascular health is one reason vitamin K2 has attracted growing scientific interest.

What Does This Mean for Heart Health?

Although these findings are promising, researchers have not yet established whether slowing coronary calcification through K2 supplementation reduces heart attacks or other cardiovascular events. Nevertheless, the study adds to growing evidence that vitamin K2 may have an important role in cardiovascular health.

Vitamin K2 also has an excellent safety profile, with studies investigating doses substantially higher than those commonly used in supplements. One important exception is for individuals taking warfarin or similar vitamin K-antagonist medications, since vitamin K can interfere with their effectiveness.

More to Come on Vitamin K2

Vitamin K2 comes in different forms. Many landmark osteoporosis studies used MK-4, often at relatively high doses, while much of the recent cardiovascular research has focused on MK-7.

In upcoming articles, we'll explore these differences, how K2 works alongside vitamin D3, and what research tells us about maintaining strong bones and healthy arteries.

Research Reference

Vossen LM, de Leeuw PW, Schurgers LJ, et al. Two Years of Menaquinone-7 Supplementation and Coronary Artery Calcification: A Randomized Clinical Trial. JAMA Cardiology. 2026;11(8):719–726. Read the study abstract.

Thinking About Vitamin K2?

Supplements aren't right for everyone, and vitamin K can interact with certain medications. Talk with your own medical provider before starting vitamin K2—especially if you take a blood thinner. If you'd like a whole-person conversation about heart and bone wellness, our naturopathic doctors are happy to help. Book a consultation.