Vitamin K2 MK-7 — Supplements
Long-acting menaquinone-7 form of vitamin K2 for calcium metabolism and cardiovascular protection.
Overview
Vitamin K2 (menaquinone-7, MK-7) is a long-chain form of vitamin K2 produced by bacterial fermentation (notably in natto). Unlike K1 (phylloquinone, which primarily supports hepatic coagulation), K2 MK-7 has a 72-hour half-life allowing daily dosing and preferentially activates extrahepatic vitamin K-dependent proteins: osteocalcin (bone mineralization) and matrix Gla protein (vascular calcification inhibition). The 3-year Knapen et al. RCT demonstrated that K2 MK-7 supplementation (180 mcg/day) improved bone strength indices and reduced age-related arterial stiffening in postmenopausal women.
Indications
- Bone mineralization and density support
- Vascular calcification prevention
- Calcium metabolism direction
- Companion to vitamin D3 supplementation
Mechanism of Action
K2 serves as cofactor for gamma-glutamyl carboxylase, activating vitamin K-dependent proteins
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Vitamin K2 (MK-7) | 100 mcg | Once daily with fat-containing meal | Always pair with vitamin D3; increase to 200 mcg for bone-specific indications |
Safety & Contraindications
- No known toxicity; no upper limit established for K2
- CRITICAL interaction with warfarin; K2 opposes warfarin's mechanism. Monitor INR closely
- Safe with other anticoagulants (DOACs) that do not work via vitamin K pathway
- Not interchangeable with K1 for coagulation purposes