Vitamin K2 (MK-7)
Plain-language research summary.
Detail
bonecardiovascularwomens-health
Orchestrates calcium placement — activates proteins that move calcium into bones and keep it out of arteries; essential complement to Vitamin D3 for women’s bone health.
Common Dietary Sources
- Natto (fermented soy; richest natural source)
- Fermented cheeses, egg yolks, some meats
How the Body Uses It
K2 (especially MK-7) activates osteocalcin and matrix Gla protein (MGP) via carboxylation, guiding calcium into bone and away from soft tissues. Works synergistically with D3 and calcium for bone maintenance.
Supplement Origins
Supplemental MK-7 is typically produced via bacterial fermentation (Bacillus subtilis natto). MK-4 is a synthetic or animal-derived short-chain form with a shorter half-life.
Possible Uses
- Supporting bone density in perimenopausal and postmenopausal women
- Complementing D3 and calcium to optimize skeletal mineralization
- Supporting vascular health via MGP activation
Long-Term Use
Suitable for long-term use at nutritional doses; consider consistency rather than large intermittent dosing due to MK-7’s long half-life.
Dose Guidance
Studied
100–200 µg/day MK-7 commonly used; higher in some trials
Take with meals containing fat to support absorption; pair with D3 and adequate calcium/magnesium.
Forms
MK-7 (menaquinone-7)
Standardization: Long half-life; once-daily; evidence for bone and arterial health
MK-4 (menaquinone-4)
Standardization: Shorter half-life; often higher-dose protocols in some regions
Delivery
Coming soon.
Evidence & Studies
Improved bone strength indices and maintained BMD vs placebo in postmenopausal women
Favorable changes in arterial stiffness measures with long-term MK-7
References
Safety & Cautions
Cautions
- Generally well tolerated at nutritional doses
- Individuals on anticoagulants require medical guidance
Contraindications
- Use with caution in patients on vitamin K–antagonist therapy (warfarin)
Interactions
- May antagonize vitamin K–antagonist anticoagulants
- Synergistic with Vitamin D3 and calcium for bone outcomes