Highlights
- Two-year MK-7 supplementation significantly reduces progression of coronary artery calcification (CAC) in symptomatic patients with coronary artery disease (CAD).
- Vitamin K2 (menaquinone-7) raises plasma MK-7 levels and decreases vascular calcification progression without notable adverse effects.
- Evidence suggests attenuation of calcification particularly in noncalcified plaques transitioning to partially calcified states, which may influence plaque stability.
- Findings contrast with heterogeneous results in populations with end-stage renal disease or severe calcifications, underscoring patient and disease stage specificity.
Background
Coronary artery calcification (CAC) is a hallmark of atherosclerosis and a robust predictor of cardiovascular events, including myocardial infarction and death. Accelerated vascular calcification is typified in patients with diabetes, chronic kidney disease, and established coronary artery disease (CAD). Matrix Gla protein (MGP), a vitamin K-dependent inhibitor of vascular calcification, requires carboxylation facilitated by vitamin K for optimal activity. Vitamin K antagonists elevate inactive MGP, promoting calcification, raising the hypothesis that vitamin K supplementation could mitigate calcification progression. However, the benefit of vitamin K in patients with symptomatic CAD, particularly involving menaquinone-7 (MK-7), a long-chain vitamin K2 homolog, has been uncertain, necessitating rigorous randomized controlled trials (RCTs).
Key Content
Chronological and Thematic Evidence Synthesis
1. VitaK-CAC Trial: MK-7 in Symptomatic CAD
The pivotal double-blind RCT by Vossen et al. (2026) enrolled 180 symptomatic patients with moderate CAC (50–400 Agatston units [AU]) randomized to MK-7 360 µg/day or placebo over 2 years. The study demonstrated a significant attenuation in CAC progression measured by CT scans: MK-7 group showed a median CAC progression of 49 AU over 2 years versus 69 AU in placebo (P=0.02). Plasma MK-7 levels rose markedly, confirming compliance and bioavailability. The study identified correlation between increased CAC scores and transformation of noncalcified plaques into partially calcified plaques, suggesting MK-7’s potential role in modulating plaque calcification dynamics. No serious adverse events were reported, underscoring safety.
2. Supplementation Outcomes in Non-CAD and ESRD Populations
Evidence from other RCTs reveals complex outcomes:
- In patients without prior ischemic heart disease but with CAC, combined vitamin K2 (720 µg/day) and vitamin D supplementation yielded no significant reduction in mean CAC progression overall, though patients with CAC ≥400 AU experienced attenuated progression and fewer cardiovascular events (Kjeldsen et al., 2023).
- In hemodialysis patients with severe vascular calcifications, MK-7 supplementation reduced inactive MGP but failed to slow CAC or aortic valve calcification progression over 18 months (Neven et al., 2023; Nawrot-Wawrzyniak et al., 2020).
- Aortic valve calcification trials with MK-7 plus vitamin D in elderly men showed no significant effect on progression, despite biochemical improvements in vitamin K status (Dalmeijer et al., 2022).
3. Ongoing and Planned Studies
Multiple large-scale trials such as the InterVitaminK and Danish multicenter studies are investigating MK-7 supplementation at various doses in aging populations with vascular calcification, assessing calcium load progression, arterial stiffness, and metabolic outcomes over 2-3 years (Kristensen et al., 2023; Jensen et al., 2023). These will further clarify MK-7’s role across different cardiovascular risk strata.
Mechanistic Insights
Vitamin K–dependent carboxylation activates MGP, which inhibits vascular smooth muscle cell osteogenic differentiation and inhibits calcium phosphate deposition. MK-7’s longer half-life and bioavailability compared to phylloquinone favor sustained MGP carboxylation. MK-7 supplementation reduces plasma levels of dephosphorylated-uncarboxylated MGP (dp-ucMGP), a biomarker linked with higher calcification burden. The VitaK-CAC study’s observed slowing of noncalcified plaque mineralization suggests MK-7 may influence plaque remodeling dynamics with possible implications on plaque stability and vulnerability. However, direct clinical evidence linking these changes to cardiovascular event reduction remains lacking.
Expert Commentary
The VitaK-CAC trial significantly advances our understanding by demonstrating that MK-7 supplementation in symptomatic CAD patients with moderate CAC can attenuate progression of coronary calcification. This is clinically relevant as CAC progression is a modifiable risk factor linked with adverse cardiovascular outcomes. The trial’s rigorous design, prolonged follow-up, and detailed imaging analyses strengthen its validity.
However, contrasting findings in patients with severe calcification or end-stage renal disease highlight the heterogeneity of vascular calcification pathophysiology and suggest patient selection and calcification stage are critical for vitamin K efficacy. The neutral results in aortic valve calcification and dialysis cohorts may be due to irreversible calcification or insufficient intervention duration/dose.
Currently, guidelines do not explicitly recommend routine vitamin K supplementation for vascular calcification prevention due to limited robust clinical outcome data. Considering the excellent safety profile and biochemical plausibility, MK-7 supplementation represents a promising adjunctive strategy. Future trials should emphasize clinical endpoints such as myocardial infarction, stroke, and mortality and include mechanistic biomarkers for stratified medicine approaches.
Conclusion
Substantial evidence from well-designed RCTs, notably the VitaK-CAC trial, supports two years of MK-7 supplementation as an effective intervention to slow progression of coronary artery calcification in symptomatic CAD patients with moderate baseline CAC. The mechanistic role of vitamin K in modulating vascular calcification via MGP activation is well established, and translation into clinical benefit appears plausible.
However, diverse results in advanced calcification and renal disease populations caution against broad generalization. Ongoing large randomized trials are anticipated to clarify the role of MK-7 supplementation across different cardiovascular risk profiles and to define its potential impact on cardiovascular morbidity and mortality.
Clinicians should consider these findings in the context of individual patient risk factors, baseline calcification burden, and the evolving evidence landscape. Future research priorities include elucidation of MK-7’s impact on plaque stability and clinical event reduction, optimal dosing strategies, and long-term safety.
References
- Vossen LM, de Leeuw PW, Schurgers LJ, et al. Two Years of Menaquinone-7 Supplementation and Coronary Artery Calcification: A Randomized Clinical Trial. JAMA Cardiol. 2026;doi:10.1001/jamacardio.2026.1279. PMID: 42268593.
- Kjeldsen KS, et al. Effects of Vitamin K2 and D Supplementation on Coronary Artery Disease in Men: A Randomized Controlled Trial. JACC Adv. 2023;2(9):100643. PMID: 38938724.
- Neven E, et al. Randomized Controlled Trial of Vitamin K2 in Hemodialysis Patients: Effect on Vascular Calcification. Kidney Int Rep. 2023;8(9):1741-1751. PMID: 37705910.
- Dalmeijer GW, et al. Vitamin K2 and D in Patients With Aortic Valve Calcification: A Randomized Double-Blinded Clinical Trial. Circulation. 2022;145(18):1387-1397. PMID: 35465686.
- Nawrot-Wawrzyniak K, et al. Vitamin K Supplementation and Arterial Calcification in Dialysis Patients: RenaKvit Trial Results. Clin Kidney J. 2021;14(9):2114-2123. PMID: 34476095.
- Kristensen SLM, et al. Study protocol of the InterVitaminK trial: Vitamin K (menaquinone-7) supplementation in general aging population. BMJ Open. 2023;13(5):e071885. PMID: 37208133.
- Jensen MK, et al. Effects of vitamins K2 and D3 supplementation in patients with severe coronary artery calcification: study protocol for a randomized controlled trial. BMJ Open. 2023;13(7):e073233. PMID: 37451735.
