K2, D3 Supplementation Reduced Coronary Artery Calcification Progression by 21% in Two Years: Study

Two years of daily supplementation with vitamin K2 as MK-7 and vitamin D2 slowed the progression of coronary artery calcification (CAC) by 21% compared to placebo in a multicenter study called Danish Coronary Decalcification (DANCODE), which utilized Balchem’s K2Vital Delta.

The findings were published in Circulation, the journal of the American Heart Association. It enrolled 398 participants, making it the largest-ever human clinical trial on the pair of vitamins to date.

The DANCODE study confirms earlier findings from the Aortic Valve Decalcification (AVADEC) trial, and extends the potential of this vitamin pairing to both men and women.  In AVADEC, the combination was shown to slow CAC progression, which is strongly associated with a higher risk of heart disease and negative cardiovascular events, in a subgroup of men with severe coronary calcification. DANCODE was conducted across three hospitals, enrolling both men and women of an average age of 71 with a CAC score of at least 400 Agatston units (AU), the standard clinical measure for severe calcification. Participants received either 720 µg/day vitamin K2 MK-7, together with 25 µg/day vitamin D3, or a placebo, for 24 months.

After the two years, calcification (measured by CT scan) had advanced in both groups, as expected at this stage. However, the progression was slower with supplementation. The data showed a mean increase of 196 AU, compared with 248 AU on placebo, representing a 21% relative reduction in calcification progression. The effect was consistent in women and men, and in participants with moderate and very high baseline calcification. For supplement brands, these findings provide support to help build consumer trust in science-backed solutions for heart health and healthy aging.

“Vitamin K2 MK-7 in its all-trans form activates matrix Gla protein, which helps direct calcium to where it is needed in the body. In this study, the reduction in calcification progression was accompanied by a marked fall in the inactive form of matrix Gla protein, which tells us the supplementation reached the pathway it was aiming for,” said Axel Diederichsen, lead author and professor at Odense University Hospital in Denmark.

“We’re so proud to see K2VITAL DELTA at the center of such a landmark study, and seeing the research published in the esteemed Circulation journal marks a real milestone for us, reinforcing our commitment to scientific excellence,” said Trygve Bergeland, nutrition science director at Balchem. “By working with hospitals and universities, we aim to help build the global evidence base behind vitamin K2. In fact, K2VITAL is the most studied vitamin K2 MK-7 in the last five years, with more participants than all other vitamin K2 manufacturers combined. We’re excited to keep up this momentum with continued investment in the partnerships and standards that drive vitamin K2 science forward.”

The DANCODE results were presented by lead author Dr Selma Hasific of Odense University Hospital at the European Society of Cardiology (ESC) Congress 2026 in Munich, one of the largest cardiovascular health meetings in the world, in August.