Vitamin K2 MK-7 — The Calcium Director
Vitamin K2 (menaquinone-7) activates matrix Gla protein (MGP) and osteocalcin — proteins that direct calcium into bones and teeth while preventing its deposition in arteries. It is the essential pairing for Vitamin D3 supplementation.
Mechanism of Action
Vitamin K2 is a cofactor for gamma-carboxylase, which activates MGP (prevents arterial calcification) and osteocalcin (promotes bone mineralization). MK-7 (from natto fermentation) has a half-life of 72 hours vs. 1–2 hours for MK-4, providing more sustained activation. K2 also activates Gas6 (cell survival signaling) and Protein S (anticoagulation).
Human Trial Evidence
The Rotterdam Study (2004, Journal of Nutrition, n=4,807) showed high menaquinone intake was associated with 57% lower coronary heart disease mortality. Multiple RCTs confirm K2 MK-7 improves bone mineral density and reduces arterial stiffness. A 2015 Thrombosis and Haemostasis RCT showed 180 µg/day MK-7 for 3 years reduced arterial stiffness by 50% in healthy postmenopausal women.
Dosing Protocol
100–200 µg/day MK-7. Always pair with Vitamin D3. Take with fat-containing meal (fat-soluble vitamin). MK-7 from natto or fermented foods is preferred. Avoid MK-4 (short half-life, requires multiple daily doses).
Safety & Contraindications
Extremely safe — no toxicity reported even at high doses. Vitamin K2 does NOT interfere with warfarin anticoagulation at doses <200 µg/day (unlike K1). However, caution is advised — monitor INR if anticoagulated. No adverse effects in pregnancy at dietary doses.