Vitamin K2 (MK-7)
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Vitamin K2 (MK-7). Activates the proteins that direct calcium into bone — not arteries.
How it works. K2 is the cofactor for γ-glutamyl carboxylase, which carboxylates osteocalcin (binds Ca to bone) and matrix Gla protein (prevents arterial calcification).
What the research supports. 3 graded claims. Strongest: Reduces arterial stiffness in postmenopausal women (moderate).
How much to take. Typical dose: 100–200 mcg MK-7/day. With largest fatty meal.
Side effects and interactions. 2 medication interactions listed. Serious: Interferes with warfarin INR control.
Stacking. Pairs well with Vitamin D3, Magnesium + Calcium. Avoid combining with Warfarin (unless monitored).
Common forms. Available as MK-7 (long half-life, daily dose), MK-4 (shorter half-life, larger doses).
Key studies. 10 studies cited. The strongest are listed with links to PubMed.
Community. Experiences from people who have tried Vitamin K2 (MK-7). Anecdotes are not medical advice.
Vitamin K2 (MK-7). Activates the proteins that direct calcium into bone — not arteries.
What it is
A fat-soluble vitamin in the K2 family. MK-7 has a 72-hour half-life vs <12 h for MK-4. Activates osteocalcin (bone) and matrix Gla protein (arteries).
Also called
Food sources
Goals
How it works
K2 is the cofactor for γ-glutamyl carboxylase, which carboxylates osteocalcin (binds Ca to bone) and matrix Gla protein (prevents arterial calcification).
Pathways
- γ-carboxylation of Gla proteins
- Bone mineralization
- Arterial calcification prevention
Effects
- +Bone mineralization supports
- ↓Arterial calcification progression decreases
- +Osteocalcin activation supports
What the research supports
Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.
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Side effects & interactions
Common side effects
- None at typical doses
Serious
- Interferes with warfarin INR control
Medication interactions
K2 directly reverses warfarin's anticoagulant effect.
Reduces absorption.
Check any supplement–medication combination with your pharmacist before starting.
Combines with
Pairs well
- Vitamin D3D3 drives Ca absorption; K2 directs it to bone, not arteries.
- Magnesium + CalciumFull bone-health stack.
Avoid combining
- Warfarin (unless monitored)Reverses anticoagulation.
Common forms
- MK-7 (long half-life, daily dose)
- MK-4 (shorter half-life, larger doses)
Key studies
10 studies cited in total.
Opens current human and preclinical literature matching Vitamin K2 (MK-7) and "Reduces arterial stiffness in postmenopausal women". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Vitamin K2 (MK-7) and "Reduces vertebral fracture risk". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Vitamin K2 (MK-7) and "Improves bone mineral density". Filter by RCT, meta-analysis, or year on the results page.
Discussion
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