Vitamin K2 (MK-7)
Also known as: Menaquinone-7, MK-7, Menatetrenone
Vitamin K2 (MK-7) acts as a co-factor for gamma-glutamyl carboxylase (GGCX), an enzyme that carboxylates glutamate residues on certain proteins, making them biologically active. Key vitamin K-dependent proteins include osteocalcin (bone health) and matrix Gla protein (MGP, vascular health). Activation of osteocalcin enables it to bind calcium to the bone matrix, improving bone mineral density. Activation of MGP inhibits arterial calcification by binding to and inactivating calcium crystals in the arterial walls. MK-7's superior bioavailability and longer half-life compared to other K vitamins allow for more sustained carboxylation of these proteins.
Last reviewed: 2026-04-22 · 4 indexed studies
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Overview
Vitamin K2, specifically menaquinone-7 (MK-7), is a fat-soluble vitamin crucial for activating proteins involved in blood clotting, bone metabolism, and vascular health. Unlike Vitamin K1 (phylloquinone), which is primarily found in leafy green vegetables and is essential for coagulation, MK-7 has a longer half-life and plays a more significant role in extrahepatic tissues, particularly in bone and arteries.
Mechanism & Function
Menaquinone-7 (MK-7) · C₄₆H₆₄O₂ — source: PubChem CID 5282140
Deep gold fermented (natto-derived) K2. Long 72-hr half-life — once-daily dosing.
- Softgel
- Capsule
- Liquid
Softgel is generally preferred for bioavailability or efficacy.
Mechanism of Action
MK-7 functions as an electron acceptor in the carboxylation of specific glutamate residues on vitamin K-dependent proteins via gamma-glutamyl carboxylase (GGCX). This carboxylation converts inactive (uncarboxylated) proteins into their active (carboxylated) forms. For example, it activates osteocalcin, allowing calcium deposition into bone, and activates matrix Gla protein (MGP), preventing soft tissue calcification, particularly in arteries. The post-translational modification is crucial for the proteins' ability to bind calcium.
Physiological Role
Vitamin K2 (MK-7) plays a critical physiological role in calcium homeostasis and vascular integrity. It modulates calcium distribution within the body, promoting its incorporation into bone and preventing its accumulation in soft tissues like arteries and kidneys. This is primarily achieved through the activation of osteocalcin for bone mineralization and matrix Gla protein (MGP) for arterial calcification inhibition. It also has a role in cell growth, metabolism, and potentially neuroprotection.
Primary Pathways
Performance / Health Relevance
While not directly impacting athletic performance in terms of acute strength or endurance, MK-7's role in bone mineral density and cardiovascular health can have long-term implications for athlete longevity and injury prevention. Stronger bones may reduce fracture risk, and healthier arteries support optimal oxygen and nutrient delivery to muscles.
Evidence Review
Compare Vitamin K Forms
Full comparison3 vitamin k forms are indexed. Bioavailability, clinical evidence, and best-use cases differ meaningfully between them.
| Form | Evidence |
|---|---|
Vitamin K2 (MK-7)This page MK-7 has excellent bioavailability and a significantly longer half-life (approx. 72 hours) compared to K1 and other K2 forms, leading to more stable serum concentrations and sustained action. | 75/100 |
| Vitamin K2 (MK-4) MK-4 has a relatively short half-life compared to MK-7, requiring more frequent or higher dosing for sustained tissue levels. It is highly bioavailable when consumed with fat. | 70/100 |
| Vitamin K1 (Phylloquinone) Fat-soluble vitamin; absorption is enhanced by dietary fat. Bioavailability from food sources, especially green leafy vegetables, can be variable due to entrapment within chloroplasts. | 65/100 |
Practical Use & Dosage
- Minimum Effective Dose
- 45 mcg/day
- Optimal Range
- 90-180 mcg/day
- Upper / Caution Level
- No established Upper Limit (UL) for MK-7 due to low toxicity, but caution with doses >1000 mcg/day in specific populations.
- Timing
- Can be taken with a meal containing fat to enhance absorption, though timing is not critical due to long half-life.
- Best Format
- Capsule or softgel containing MK-7, often derived from natto (fermented soybeans) or synthetically produced.
- Bioavailability
- MK-7 has excellent bioavailability and a significantly longer half-life (approx. 72 hours) compared to K1 and other K2 forms, leading to more stable serum concentrations and sustained action.
- Absorption Considerations
- Fat-soluble vitamin; absorption is enhanced when consumed with dietary fat. Individuals with fat malabsorption conditions may require higher doses or specific formulations.
Safety & Interactions
Side Effects
- •Generally well-tolerated, rare gastrointestinal upset at very high doses.
Contraindications
- Individuals on anticoagulant medications (e.g., warfarin) due to potential interference with drug action.
Drug Interactions
- •Anticoagulants (warfarin): Vitamin K antagonizes the action of warfarin. Concomitant use requires careful monitoring of INR.
- •Orlistat: May reduce absorption of fat-soluble vitamins, including K2.
- •Bile acid sequestrants (e.g., cholestyramine): May reduce absorption of fat-soluble vitamins.
Who Should Avoid
- •Individuals on warfarin unless under strict medical supervision and dose adjustment.
Monitoring
Individuals on warfarin should monitor INR closely when initiating or discontinuing K2 supplementation. Otherwise, no specific monitoring is generally required at typical doses.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Vitamin K2 (MK-7) typically used or indicated?
Vitamin K2 (MK-7) is most commonly used for: Bone Health, Cardiovascular Health, Calcium Metabolism. Vitamin K2 (MK-7) plays a critical physiological role in calcium homeostasis and vascular integrity. It modulates calcium distribution within the body, promoting its incorporation into bone and preventing its accumulation in soft tissues like arteries and kidneys. This is primarily achieved through the activation of osteocalcin for bone mineralization and matrix Gla protein (MGP) for arterial calcification inhibition. It also has a role in cell growth, metabolism, and potentially neuroprotection.
How does Vitamin K2 (MK-7) work?
MK-7 functions as an electron acceptor in the carboxylation of specific glutamate residues on vitamin K-dependent proteins via gamma-glutamyl carboxylase (GGCX). This carboxylation converts inactive (uncarboxylated) proteins into their active (carboxylated) forms. For example, it activates osteocalcin, allowing calcium deposition into bone, and activates matrix Gla protein (MGP), preventing soft tissue calcification, particularly in arteries. The post-translational modification is crucial for the proteins' ability to bind calcium.
What is the recommended dose of Vitamin K2 (MK-7)?
The optimal range is 90-180 mcg/day. with a minimum effective dose of 45 mcg/day. Best taken: Can be taken with a meal containing fat to enhance absorption, though timing is not critical due to long half-life.. Upper / caution level: No established Upper Limit (UL) for MK-7 due to low toxicity, but caution with doses >1000 mcg/day in specific populations..
What are the side effects of Vitamin K2 (MK-7)?
Reported side effects include: Generally well-tolerated, rare gastrointestinal upset at very high doses.. Monitoring: Individuals on warfarin should monitor INR closely when initiating or discontinuing K2 supplementation. Otherwise, no specific monitoring is generally required at typical doses.
Does Vitamin K2 (MK-7) interact with medications?
Known or theoretical interactions: Anticoagulants (warfarin): Vitamin K antagonizes the action of warfarin. Concomitant use requires careful monitoring of INR.; Orlistat: May reduce absorption of fat-soluble vitamins, including K2.; and Bile acid sequestrants (e.g., cholestyramine): May reduce absorption of fat-soluble vitamins.. Always check with a clinician before combining with prescription medication.
Who should avoid Vitamin K2 (MK-7)?
Vitamin K2 (MK-7) is generally not recommended for: Individuals on warfarin unless under strict medical supervision and dose adjustment.; and Individuals on anticoagulant medications (e.g., warfarin) due to potential interference with drug action..
How strong is the evidence for Vitamin K2 (MK-7)?
Evidence level: Strong (overall score 75/100), based on 4 indexed studies on SuppIndex.
Research & References (4)
Menaquinone-7 Supplementation Improves Arterial Stiffness in Healthy Postmenopausal Women: A Randomized Controlled Trial
This study investigated the effect of MK-7 supplementation on arterial stiffness and vascular calcification in healthy postmenopausal women. Participants received either MK-7 or placebo for three years.
Vitamin K2 (menaquinone-7) in the prevention of age-related diseases: an evidence-based narrative review
This review summarizes the current evidence regarding the role of menaquinone-7 in preventing age-related diseases, focusing on bone and cardiovascular health.
Vitamin K2 and Bone Health: A Comprehensive Review of Human Studies
This systematic review comprehensively examines human studies on the effects of vitamin K2 (MK-4 and MK-7) on bone health, including bone mineral density and fracture risk.
The effect of menaquinone-7 (vitamin K2) supplementation on bone health in osteopenic postmenopausal women
This randomized, double-blind, placebo-controlled trial investigated the effect of MK-7 supplementation on lumbar spine and femoral neck bone mineral density (BMD) in osteopenic postmenopausal women.
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Research Overview
Strong EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/vitamin-k2-mk-7
SuppIndex. (2026). Vitamin K2 (MK-7): Evidence summary, dosage and clinical studies. Retrieved October 23, 2026, from https://thesuppindex.com/ingredients/vitamin-k2-mk-7
Based on 4 indexed studies · Evidence level: Strong.
Goal Ratings
Stack Compatibility
Frequently stacked with Vitamin D3, Calcium, and Magnesium for synergistic effects on bone health. Compatible with most other supplements.