Our pick · Vitamin K2 (MK-7)

Thorne Vitamin K (K1 + K2 MK-4/MK-7)

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Vitamin K2 (MK-7)

Directs calcium toward bones and teeth and away from arteries — promising evidence for cardiovascular and skeletal health, especially alongside vitamin D.

By editorialUpdated 2026-05-251 min read

What it's actually good for

Vitamin K2 (particularly the MK-7 form) activates proteins that direct calcium into bones and teeth while keeping it out of soft tissues like arteries. Observational data from the Rotterdam Study showed that higher dietary K2 intake was associated with significantly lower cardiovascular mortality, and small RCTs support improvements in arterial stiffness. For bone health, K2 supports osteocalcin activation, and Japanese data on high-dose MK-4 shows fracture reduction. The evidence is promising but not yet definitive from large Western RCTs — making it a reasonable addition for those concerned about vascular or skeletal health, particularly when paired with vitamin D3.

Claim-by-claim

Each claim graded independently

The overall grade is the floor. Some claims are stronger or weaker than the headline.

B

Supports arterial health by activating matrix Gla-protein to inhibit vascular calcification

Observational studies (Rotterdam Study) link higher K2 intake with reduced cardiovascular mortality. MK-7 supplementation trials show improved arterial stiffness markers, though large-scale RCTs are still ongoing.

B

Supports bone mineral density and may reduce fracture risk

Japanese trials with MK-4 (high dose) show fracture reduction; MK-7 trials show improved bone turnover markers. Evidence is stronger in post-menopausal women with low vitamin K status.

Sources

1 cited
[01]GOVTVitamin K — Fact Sheet for Health ProfessionalsNIH Office of Dietary Supplements. 2024

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Medical disclaimer. The information on this site is provided for educational purposes only and is not intended as medical advice. It does not constitute a diagnosis, treatment plan, or recommendation for any specific health condition. Always consult a qualified healthcare professional before making changes to your supplement regimen, diet, or lifestyle — especially if you are pregnant, nursing, taking medications, or managing a medical condition.

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