What is MK-7 and How Does It Work?
MK-7, or menaquinone-7, is a specific type of vitamin K2 that has garnered significant attention for its remarkable health benefits, particularly for bones and heart health. As a fat-soluble vitamin, MK-7 plays a crucial role in activating vitamin K-dependent proteins (VKDPs) throughout the body. These proteins, such as osteocalcin and matrix Gla protein (MGP), are essential for proper calcium metabolism.
Unlike vitamin K1, found primarily in leafy greens, MK-7 is synthesized through bacterial fermentation. This process makes it highly bioavailable and gives it a longer half-life in the bloodstream compared to other forms of vitamin K2, like MK-4. This extended presence allows MK-7 to work more effectively on tissues outside the liver, such as bones and blood vessels.
The Calcium Paradox and MK-7's Role
Without adequate MK-7, the body can fall victim to what is known as the "calcium paradox." This is a scenario where calcium is absorbed from the gut but fails to be properly integrated into bones, instead depositing in soft tissues like arteries and blood vessels. MK-7 acts like a "traffic cop," directing calcium to where it is needed—in the bones and teeth—and keeping it out of the arteries. This is accomplished by activating two key proteins:
- Osteocalcin: Produced by bone-building cells (osteoblasts), osteocalcin is responsible for binding calcium to the bone matrix. MK-7 activates this protein, ensuring strong bone mineralization.
- Matrix Gla Protein (MGP): This protein is produced in the vascular walls and is the most potent known inhibitor of arterial calcification. MK-7's activation of MGP helps keep arteries flexible and healthy, promoting smooth blood flow.
The Key Benefits of MK-7
Supporting Strong Bones and Preventing Osteoporosis
MK-7's primary benefit is its powerful effect on bone health. Research has shown that MK-7 stimulates osteoblastic bone formation while suppressing osteoclastic bone resorption. Studies in postmenopausal women, a group at high risk for osteoporosis, have demonstrated that MK-7 supplementation can help maintain bone mineral density and strength. Its synergistic relationship with vitamin D3 is also crucial, as D3 increases calcium absorption, and MK-7 ensures that calcium is properly utilized for bone health.
Promoting Cardiovascular Health
By activating MGP, MK-7 actively prevents arterial calcification, a major risk factor for heart disease. The Rotterdam Study, a long-term observational study, found a strong inverse association between high dietary MK-7 intake and reduced risk of coronary heart disease and mortality. Clinical trials have also indicated that MK-7 supplementation can improve arterial stiffness and elasticity, especially in those with high levels of calcification.
Other Emerging Health Benefits
Beyond its well-established roles in bone and heart health, new research is exploring additional benefits of MK-7, including potential effects on:
- Inflammation modulation
- Brain and nerve health
- Cellular growth regulation
- Metabolic conditions like diabetes
How to Get MK-7 into Your Diet
One of the best natural sources of MK-7 is the traditional Japanese dish natto, a fermented soybean product. However, since natto has a strong, pungent flavor that is not palatable to everyone, many people choose to obtain their MK-7 from supplements. Other fermented foods and animal products, like aged cheese and liver, contain smaller amounts.
It is important to remember that as a fat-soluble vitamin, MK-7 is best absorbed when consumed with a meal containing some fat.
MK-7 vs. MK-4: The Key Difference
Understanding the distinction between MK-7 and MK-4 is crucial for those considering supplementation. Both are forms of vitamin K2, but they differ significantly in bioavailability and effect.
| Feature | MK-7 (Menaquinone-7) | MK-4 (Menaquinone-4) |
|---|---|---|
| Primary Source | Bacterial fermentation (e.g., natto) | Animal products (e.g., eggs, liver, butter) or conversion from K1 |
| Half-Life | Long (remains in bloodstream for days) | Short (cleared from the body within hours) |
| Availability | Effective at lower, nutritional levels | Requires larger amounts for extrahepatic action |
| Bioavailability | Excellent; easily absorbed and accumulates in the body | Poor at nutritional levels for extrahepatic action; most doesn't show up in the blood |
| Action | Reaches extrahepatic tissues (bones, arteries) more effectively | Primarily acts in the liver at nutritional levels |
The longer half-life of MK-7 makes it a more effective and convenient option for consistent delivery to non-hepatic tissues like bone and arteries, which is why it is the preferred choice for most K2 supplements.
Conclusion
In conclusion, what is MK 7 good for extends well beyond a single benefit. This potent form of vitamin K2 is a game-changer for directing calcium metabolism, providing robust support for bone mineralization and cardiovascular health. Its superior bioavailability and prolonged activity in the body make it more effective than other forms of vitamin K2 for these extrahepatic functions. By helping to integrate calcium into the skeletal structure while keeping it out of the arteries, MK-7 plays a preventative and therapeutic role in age-related conditions like osteoporosis and arterial calcification. For those looking to support their long-term bone and heart health, ensuring an adequate intake of MK-7 through diet or supplementation is a powerful strategy.
Clinical trial on MK-7 for arterial stiffness
Important Considerations and Contraindications
While MK-7 is generally considered safe, it is a form of vitamin K and can interact with blood-thinning medications like warfarin. Patients on such medication should consult a healthcare provider before taking any MK-7 supplements. Caution is also advised for individuals with liver disease or those with hereditary coagulation disorders.
