What is Vitamin K2 MK-7?
Vitamin K is a family of fat-soluble vitamins crucial for blood coagulation, bone metabolism, and heart health. While vitamin K1 (phylloquinone) is found in green leafy vegetables, vitamin K2 (menaquinone) is predominantly found in fermented foods and animal products. The K2 family has several subtypes, numbered MK-4 through MK-13, with MK-7 being particularly notable. MK-7 is highly sought after for its superior bioavailability and longer half-life compared to other forms of vitamin K, meaning it remains active in the body for an extended period. It works synergistically with vitamin D3 to optimize calcium distribution in the body.
The Health Benefits of MK-7
Including MK-7 in your nutrition plan provides significant health advantages, primarily through its role in calcium metabolism:
- Bone Health: MK-7 activates a protein called osteocalcin, which binds calcium to the bone matrix, strengthening bones and reducing the risk of osteoporosis and fractures.
- Cardiovascular Health: It activates another protein, matrix GLA-protein (MGP), which helps prevent calcium from accumulating in arteries and soft tissues. This reduces arterial stiffness and calcification, supporting heart health.
- Dental Health: Similar to its function in bones, MK-7 supports the mineralization of teeth, which is crucial for preventing cavities and promoting strong dental health.
- Synergy with Vitamin D: MK-7 partners with vitamin D3 to ensure that the calcium absorbed by the body is directed to the bones and teeth where it is needed most, rather than accumulating in blood vessels.
Dietary Sources of Vitamin K2 MK-7
Acquiring sufficient MK-7 from diet can be challenging, as it is not widespread in typical Western diets. The best sources are fermented foods and certain animal products.
The absolute best source is natto—a traditional Japanese dish of fermented soybeans. Natto is made by fermenting soybeans with the bacterium Bacillus subtilis, which produces exceptionally high concentrations of MK-7. For those unaccustomed to its strong taste and slimy texture, incorporating it into meals may be an acquired taste. However, a small serving can provide a very substantial amount of MK-7.
Beyond natto, other food sources exist, though they contain significantly less MK-7:
- Fermented Foods: Sauerkraut and other fermented vegetables can contain MK-7, produced during the fermentation process by bacteria.
- Cheeses: Certain aged or fermented cheeses, such as Gouda, Brie, and Edam, are moderate sources of various menaquinones, including some MK-7. Full-fat, fermented cheeses tend to have higher levels.
- Animal Products: Some animal-based foods, particularly from grass-fed animals, contain MK-7. This includes chicken (especially liver) and grass-fed butter.
Supplementation as an Alternative
For individuals who find it difficult to regularly consume natto or other MK-7 rich foods, or who are following a vegan diet, supplementation is a highly effective and reliable option. MK-7 supplements are widely available, often derived from natto or fermented chickpeas. They are commonly sold alone or in combination with Vitamin D3 to maximize calcium utilization and absorption.
When choosing a supplement, consider the following:
- Source: Look for supplements that specify their MK-7 source, such as natto or fermented chickpeas, which are known to be high-quality options.
- Fat-Solubility: As a fat-soluble vitamin, MK-7 is best absorbed when taken with a meal containing some fat. Many supplements already include a fatty acid to improve absorption.
- Consult a Professional: A healthcare professional can help determine an appropriate approach for your needs.
Comparison of Vitamin K2 MK-7 and MK-4
While MK-7 is known for its bioavailability and longer half-life, it's important to understand how it differs from MK-4, another prevalent form of vitamin K2.
| Feature | Vitamin K2 MK-7 | Vitamin K2 MK-4 |
|---|---|---|
| Source | Primarily from bacterial fermentation (e.g., natto, sauerkraut, some cheeses) | Found in animal products (e.g., eggs, liver, grass-fed butter) |
| Bioavailability | Excellent; more readily absorbed than K1 | Also well absorbed, but MK-7 is often favored for efficacy |
| Half-Life | Long half-life, providing sustained activity in the body | Shorter half-life, requiring more frequent intake |
| Distribution | Concentrates in soft tissues and arteries, crucial for cardiovascular health | Found in tissues like the pancreas and liver, important for localized function |
| Typical Intake | Often requires supplementation for adequate intake in Western diets | Can be obtained through diet if sufficient animal products are consumed |
Maximizing Your MK-7 Absorption
To get the most out of your MK-7 intake, whether from food or supplements, consider these strategies:
- Eat with Fat: Always consume MK-7 sources alongside a meal containing some dietary fat. This enhances absorption, as it is a fat-soluble vitamin.
- Consider Vitamin D: MK-7 and Vitamin D have a synergistic relationship. Ensure you have adequate Vitamin D levels to maximize MK-7's benefits, especially for bone health.
- Diversify Your Diet: While natto is the richest source, incorporating a variety of fermented foods and grass-fed animal products can provide a broader spectrum of menaquinones.
Important Considerations
Before making significant changes to your vitamin K intake, especially through supplements, it is crucial to consult a healthcare professional. This is particularly important for individuals on anticoagulant medications, such as warfarin, where changes in vitamin K levels can interfere with treatment. They can help determine a safe and effective approach based on your individual health needs.
Conclusion
Obtaining vitamin K2 MK-7 is an important step toward supporting bone and heart health. While the traditional Japanese food natto offers the highest dietary concentration, fermented foods and certain animal products also provide beneficial amounts. For consistent and reliable intake, high-quality supplements offer an excellent alternative, often combined with vitamin D3 for optimal calcium metabolism. By understanding the best sources and how to enhance absorption, you can effectively integrate this powerful nutrient into your diet to support your long-term health. For more research and insights, the National Institutes of Health provides comprehensive information on vitamin K.
Disclaimer: This information is for general knowledge and should not be taken as medical advice. Consult with a healthcare professional before starting any new supplement regimen or making significant dietary changes.
