As we age, calcium can accumulate in the arterial walls—a process known as vascular calcification that increases arterial stiffness and elevates cardiovascular risk. A comprehensive meta-analysis of 14 randomized controlled trials (1,500+ participants) published in Frontiers in Nutrition evaluated whether vitamin K can slow this progression.

Key Study Findings

Across the included trials, vitamin K supplementation (both K1 and K2) demonstrated clear vascular benefits:

• Slower Progression: Reduced the rate of coronary artery calcification (CAC).
• Improved Biomarkers: Significantly decreased inactive matrix Gla protein (dp-ucMGP), allowing MGP to properly inhibit arterial calcium deposition.
• Safety: Showed no increase in adverse events compared to placebo.

Dietary Sources & Considerations

Vitamin K helps direct calcium into the bones and away from soft tissues like blood vessels. Vitamin K1 is abundant in leafy greens (spinach, kale), while vitamin K2 (MK-7)—which features a longer active half-life in the body—is found primarily in fermented foods like natto and aged cheeses.

Note on Oxalates: While green leafy foods supply K1, high-oxalate greens can place stress on the kidneys. Pairing them with dietary calcium and staying well-hydrated helps mitigate crystal formation. Individuals on blood thinners should always consult a physician before supplementing with vitamin K.

Reference

Vitamin K supplementation and vascular calcification: a systematic review and meta-analysis of randomized controlled trials