Does vitamin K2 actually prevent calcium from building up in arteries, or is that claim ahead of the evidence?

The evidence is now more than a theoretical mechanism, but the claim needs boundaries. In the 2026 DANCODE trial, 398 participants with severe coronary artery calcification were studied over two years. Those assigned vitamin K2 plus vitamin D3 had a smaller increase in calcium score than those assigned placebo. Both groups’ scores still increased, so this was slower progression, not arteries being “decalcified.” The treatment combined two vitamins and was tested in an older, heavily calcified population; it does not isolate K2’s effect or establish the same benefit in healthy young adults.[1]

A calcium scan is also not the same endpoint as a heart attack, stroke or lifespan. DANCODE does not establish that supplementation prevents those events, and the imaging subset did not show a reduction in total plaque progression. The result is promising, but it is not a substitute for managing LDL, blood pressure and smoking. Vitamin K participates in activation of proteins involved in calcification regulation, which gives the research a biological rationale. It also interacts with vitamin K antagonist anticoagulants such as warfarin, so changes in supplementation need coordination with the prescribing clinician.[1][2]