What is Vitamin K2 as MK7?
Vitamin K is a fat-soluble vitamin known for its role in blood clotting. However, the lesser-known vitamin K2, or menaquinone, is increasingly recognized for its distinct and vital functions in calcium metabolism, a process crucial for both skeletal and cardiovascular wellness. MK7 (menaquinone-7) is a specific, long-chain form of vitamin K2, primarily produced by bacteria during the fermentation of foods like natto. Its longer half-life compared to other forms, such as MK4, allows it to remain active in the body's circulation for an extended period, ensuring better efficacy and wider distribution to target tissues like bones and arteries.
The Role of MK7 in Bone Health
One of the most significant functions of MK7 is its contribution to bone health. It works by activating osteocalcin, a protein produced by bone-building cells known as osteoblasts.
- Activates Osteocalcin: In its inactive form, osteocalcin cannot bind to calcium. MK7 acts as a necessary cofactor for the enzyme that carboxylates osteocalcin, converting it into an active form that can then bind and direct calcium to the bone matrix.
- Enhances Bone Mineralization: By guiding calcium to the bones, activated osteocalcin promotes proper bone mineralization and density. This process is essential for maintaining strong, healthy bones and can be particularly beneficial for aging individuals and postmenopausal women at higher risk for osteoporosis.
- Inhibits Bone Resorption: Research indicates that MK7 also helps prevent bone resorption, the process where bone tissue is broken down. It upregulates osteoprotegerin, a protein that interferes with the formation of osteoclasts (cells that resorb bone), thus contributing to a favorable balance between bone formation and breakdown.
How MK7 Protects Cardiovascular Health
Beyond its role in bone health, MK7 is a powerful ally for the cardiovascular system, primarily by managing calcium distribution.
- Activates MGP: MK7 activates Matrix Gla Protein (MGP), another vitamin K-dependent protein. MGP is a critical inhibitor of vascular calcification, a condition where calcium deposits build up in the arteries and blood vessels.
- Prevents Arterial Stiffness: By keeping calcium out of the arteries and soft tissues, MK7 helps maintain arterial elasticity and flexibility. Multiple clinical trials have shown that MK7 supplementation can improve arterial stiffness, especially in individuals with high baseline arterial stiffness.
- Optimizes Calcium Utilization: The synergistic relationship between vitamin D3 and MK7 is crucial here. While vitamin D3 boosts calcium absorption from the gut, MK7 ensures this absorbed calcium is directed toward bone tissue rather than settling in the arteries.
Sources of MK7
MK7 is naturally present in certain foods, and can also be obtained via supplementation.
Food Sources:
- Natto: This traditional Japanese fermented soybean dish is the most potent dietary source of MK7.
- Fermented Cheeses: Aged and hard cheeses, like Gouda, Camembert, and Swiss cheese, contain notable levels of MK7.
- Sauerkraut: Fermented cabbage contains smaller amounts of MK7, and is also a source of vitamin K1.
- Animal Products: Some animal products contain varying levels of MK7, although the amounts are generally lower than in fermented foods.
Supplementation:
- For those who don't regularly consume MK7-rich foods, supplements are a convenient option. MK7 supplements, often combined with vitamin D3, are widely available.
- The bioavailability of MK7 from supplements is generally high, ensuring your body can effectively utilize it.
Comparison: MK7 vs. MK4
While both MK7 and MK4 are forms of vitamin K2, they differ significantly in their bioavailability and effects.
| Feature | MK7 (Menaquinone-7) | MK4 (Menaquinone-4) |
|---|---|---|
| Source | Produced by bacteria during fermentation (e.g., natto), and some animal products. | Produced from vitamin K1 conversion in animal tissues (e.g., liver, egg yolks). |
| Bioavailability | High absorption and remains in the blood for days. | Rapidly cleared from circulation within 6-8 hours. |
| Half-Life | Long half-life, providing sustained benefits. | Short half-life, requiring multiple daily doses for sustained effect. |
| Efficacy for Bone Health | Very effective at activating osteocalcin and supporting long-term bone health. | Can activate osteocalcin, but requires higher, more frequent doses. |
| Systemic Impact | Distributed effectively to extrahepatic tissues like bones and arteries. | Primarily utilized by the liver for blood clotting, with limited distribution elsewhere. |
Potential Health Benefits Beyond Bones and Heart
Emerging research suggests MK7 may offer a range of other benefits for the body.
- Supports Brain Health: Some studies indicate that vitamin K2, including MK7, plays a role in cognitive function and may help protect against neurodegenerative diseases like Alzheimer's.
- Promotes Dental Health: By helping activate proteins like osteocalcin, MK7 contributes to the proper mineralization of teeth, enhancing their strength and integrity.
- Regulates Insulin Levels: Research suggests a link between MK7 supplementation and improved insulin response, which could be beneficial for individuals with type 2 diabetes.
- Anti-inflammatory Properties: MK7 has been shown to suppress proinflammatory mediators, which may contribute to its protective effects against chronic degenerative conditions.
Conclusion
In summary, MK7 is a potent, fat-soluble form of vitamin K2 that provides a multitude of benefits for the human body. Its primary functions revolve around directing calcium to where it's needed most: the bones and teeth. This not only strengthens the skeletal system and helps prevent osteoporosis but also actively inhibits the calcification of arteries and blood vessels, thereby supporting long-term cardiovascular health. With its high bioavailability and long half-life, MK7 offers a reliable way to optimize calcium metabolism. Whether through dietary sources like natto and aged cheese or through supplementation, ensuring adequate MK7 intake is a proactive step toward maintaining robust bone and heart health as you age. As always, it is recommended to speak with a healthcare provider before beginning any new supplement regimen.
Disclaimer
Please consult with a healthcare professional before starting any new supplement regimen, especially if you are pregnant, nursing, taking medication (particularly blood thinners like warfarin), or have any pre-existing medical conditions.
