Can vitamin K (Vit K) supplementation reduce coronary artery calcium scores?

Vitamin K Supplementation and Coronary Artery Calcium Scores

Vitamin K supplementation has shown inconsistent effects on reducing coronary artery calcium scores, with some evidence suggesting potential benefit in specific populations with high baseline calcium scores, but insufficient evidence to recommend routine supplementation for this purpose.

Current Evidence on Vitamin K and Vascular Calcification

• The 2025 KDIGO Controversies Conference reported mixed results from clinical trials examining vitamin K supplementation for vascular calcification in chronic kidney disease (CKD) patients 1
• The VitaVasK pilot trial showed significant reductions in thoracic aorta calcification progression with vitamin K1 supplementation in hemodialysis patients, but the difference in coronary artery calcification did not reach statistical significance 1
• A 2023 randomized controlled trial in men without ischemic heart disease found that vitamin K2 (720 μg/day) and vitamin D (25 μg/day) supplementation showed no significant overall reduction in mean coronary artery calcium (CAC) progression over 2 years compared to placebo 2
• However, in a subgroup analysis of patients with CAC scores ≥400 AU, the same study found significantly lower CAC progression in the vitamin K2 and D supplementation group (Δ288 vs Δ380 AU, P = 0.047) 2

Mechanism of Action

• Vitamin K is essential for activating matrix Gla protein (MGP), a vitamin K-dependent protein in vascular tissue that inhibits vascular calcification 3
• Vitamin K deficiency leads to undercarboxylated MGP, which is associated with increased vascular calcification 3, 4
• In animal models, vitamin K2 supplementation has been shown to attenuate the progression of atherosclerosis and coronary calcification 5

Special Considerations for Specific Populations

• For patients with CKD on dialysis, who are at high risk for vascular calcification, vitamin K supplementation may have potential benefits, but evidence remains inconsistent 1, 3
• Patients on warfarin (vitamin K antagonist) may have increased coronary artery calcification due to inhibition of vitamin K-dependent proteins, but supplementation could interfere with anticoagulation 5
• The 2020 KDOQI Clinical Practice Guidelines specifically recommend that patients receiving anticoagulant medicines that inhibit vitamin K activity (e.g., warfarin) should not receive vitamin K supplements 1

Safety Considerations

• A 2023 study reported fewer safety events (composite of myocardial infarction, coronary revascularization, and all-cause mortality) in participants receiving vitamin K2 and D supplementation compared to placebo (1.9% vs 6.7%, P = 0.048) 2
• Vitamin K supplementation appears to be generally safe with no reported adverse effects associated with vitamin K2 use in clinical trials 6
• There is no evidence that vitamin K supplementation increases cardiovascular risk 4

Current Recommendations

• There are currently no established guidelines specifically recommending vitamin K supplementation for reducing coronary artery calcium scores in the general population 1
• The 2013 New England Journal of Medicine clinical practice guidelines on calcium supplements and fracture prevention did not address vitamin K supplementation for vascular calcification 1
• The 2015 Cochrane review on vitamin K for primary prevention of cardiovascular disease highlighted the lack of evidence to determine effectiveness and called for further high-quality trials 4

Ongoing Research

• Several clinical trials are currently investigating the effects of vitamin K supplementation on vascular calcification, including:
  • The iPACK-HD trial examining vitamin K supplementation in hemodialysis patients 3
  • A randomized controlled trial of vitamin K2 and D3 supplementation in patients with severe coronary artery calcification (CAC score ≥400) 6

Practical Approach

• For patients with high coronary artery calcium scores (≥400 AU), vitamin K2 supplementation might be considered as an adjunctive therapy, particularly if there are no contraindications 2
• For patients with CKD, especially those on dialysis, vitamin K supplementation might have potential benefits for reducing vascular calcification progression, but more definitive evidence is needed 1, 3
• Patients on warfarin should not receive vitamin K supplements due to potential interference with anticoagulation 1, 5
• For general cardiovascular health, focus on established preventive strategies (lipid management, blood pressure control, smoking cessation) rather than relying on vitamin K supplementation alone 4