Are You Getting the Right Type of Vitamin K2? Understanding MK-4 and MK-7 Differences

Vitamin K is essential for many bodily functions, including blood clotting and bone health. While Vitamin K1 is well-known for its role in blood coagulation, Vitamin K2 is gaining attention for its benefits for bone and heart health. Vitamin K2 comes in several forms, with MK-4 and MK-7 being the most studied. Understanding the differences between these two forms can help you make informed decisions about your health.

What is Vitamin K2?

Vitamin K2 is a fat-soluble vitamin that plays a critical role in calcium metabolism. Unlike Vitamin K1, which is primarily involved in blood clotting, Vitamin K2 helps direct calcium to the bones and teeth, preventing it from depositing in the arteries and soft tissues. This function is crucial for maintaining bone density and cardiovascular health.

Vitamin K2 is naturally found in certain animal products and fermented foods. The body also produces a small amount of Vitamin K2 in the gut, thanks to bacteria.

Vitamin K2 Subtypes: MK-4 and MK-7

What is MK-4?

MK-4 is a subtype of Vitamin K2 found in animal products such as meat, eggs, and dairy. It is also present in some fermented foods. MK-4 has a short half-life in the body, meaning it is quickly absorbed and utilized. This subtype is often used in supplements and has been shown to benefit bone health.

What is MK-7?

MK-7 is another important subtype of Vitamin K2, found in fermented foods like natto (fermented soybeans), certain cheeses, and some dietary supplements. Unlike MK-4, MK-7 has a much longer half-life, allowing it to remain active in the body for extended periods. This makes MK-7 particularly effective in maintaining bone and cardiovascular health over time.

Health Benefits of MK-4 and MK-7

Bone Health

Both MK-4 and MK-7 play vital roles in bone health by activating proteins that bind calcium to the bone matrix, increasing bone density and strength. MK-4 has been shown to improve bone mineralization, while MK-7, with its longer half-life, provides a sustained benefit, potentially leading to greater improvements in bone density over time.

Cardiovascular Health

MK-4 and MK-7 also contribute to cardiovascular health by preventing the calcification of arteries. MK-4 has been shown to reduce arterial calcification, a major risk factor for heart disease. MK-7, on the other hand, has been linked to a reduction in cardiovascular events such as heart attacks and strokes. Studies indicate that regular intake of MK-7 can significantly decrease the risk of heart disease by preventing calcium buildup in the arteries ¹.

Cancer Prevention

Research suggests that both MK-4 and MK-7 may have anti-cancer properties ². MK-4 has been shown to inhibit the growth of certain cancer cells, while MK-7 can reduce the activity of proteins associated with tumour growth. These findings highlight the potential of Vitamin K2 in cancer prevention, though more research is needed to confirm these benefits.

Other Potential Benefits

In addition to bone and cardiovascular health, MK-4 and MK-7 may benefit dental health by preventing calcification in the teeth, supporting kidney health, and improving overall longevity by maintaining proper calcium balance in the body.

Absorption and Bioavailability

Comparison of Absorption Rates

MK-4 and MK-7 differ in their absorption rates and bioavailability. MK-4 is quickly absorbed and utilized by the body, making it effective for short-term benefits. However, its rapid metabolism means it needs to be consumed more frequently. MK-7, with its longer half-life, remains in the body for extended periods, providing sustained benefits with less frequent intake.

Synergistic Effects with Vitamin D

Combining Vitamin K2 with Vitamin D can enhance the benefits of both vitamins. Vitamin D improves calcium absorption in the gut, while Vitamin K2 directs calcium to the bones and prevents it from depositing in the arteries. This synergy maximizes the effectiveness of both vitamins, promoting better bone and cardiovascular health.

Factors Affecting Absorption

Several factors can influence the absorption and effectiveness of MK-4 and MK-7, including dietary fat intake, gut health, and the presence of other nutrients. Consuming these vitamins with a fat-containing meal can improve their absorption, as they are fat-soluble vitamins. Additionally, maintaining a healthy gut microbiome supports the production and absorption of Vitamin K2.

Recommended Daily Intake and Safety

Recommended Daily Intake

The recommended daily intake of Vitamin K2 varies based on age, sex, and health conditions. For adults, a typical dosage ranges from 90 to 120 micrograms per day. However, specific recommendations for MK-4 and MK-7 are not well-established, and more research is needed to determine optimal intake levels for these subtypes.

Safety and Potential Toxicity

Vitamin K2 has a very low potential for toxicity, and there is no established upper intake level. However, individuals taking blood thinners such as warfarin should be cautious, as Vitamin K can interfere with the medication’s effects. It is important to maintain consistent Vitamin K intake and consult with a healthcare provider before making any changes to your diet or supplement regimen.

Interactions with Medications

People on blood-thinning medications need to be particularly careful with Vitamin K intake. Both MK-4 and MK-7 can interact with these medications, affecting blood clotting. Consistent daily intake of Vitamin K is crucial to avoid fluctuations that could lead to adverse effects. Always consult a healthcare provider before starting any new supplement, especially if you are on medication.

Guidelines for Specific Health Conditions

Individuals with gastrointestinal conditions such as celiac disease or ulcerative colitis may have an increased risk of Vitamin K deficiency. These conditions can impair the absorption of fat-soluble vitamins, including Vitamin K2. People with these health issues should discuss their Vitamin K needs with a healthcare provider to ensure they are getting adequate amounts through diet or supplements.

Dietary Sources and Supplementation

Best Dietary Sources of MK-4 and MK-7

Vitamin K2 can be found in various foods, though the sources differ between MK-4 and MK-7.

• MK-4 Sources:
• Animal products such as meat, liver, eggs, and dairy
• Some fermented foods, although less common than those rich in MK-7
• MK-7 Sources:
• Fermented foods like natto (fermented soybeans), which is particularly high in MK-7
• Certain cheeses, such as gouda and blue cheese, also contain significant amounts of MK-7
• Other fermented products, including sauerkraut and kefir, though in lesser amounts than natto

Advantages and Disadvantages of Dietary Sources vs. Supplements

• Dietary Sources:
• Natural foods provide a complex matrix of nutrients that can enhance the bioavailability of Vitamin K2
• Consuming Vitamin K2 in food can be more enjoyable and sustainable for many people
• However, the availability of MK-4 and MK-7-rich foods may be limited based on dietary preferences and geographic location
• Supplements:
• Supplements offer a convenient way to ensure consistent intake of MK-4 and MK-7, especially for those with limited access to natural sources
• They can provide higher doses of Vitamin K2, which might be necessary for individuals with specific health conditions or increased needs
• Potential disadvantages include cost, the need to remember daily intake, and possible interactions with medications

Tips for Choosing the Right Vitamin K2 Supplement

• Look for supplements that specify the form of Vitamin K2 they contain (MK-4 or MK-7)
• Check the dosage to ensure it meets your dietary needs without exceeding the recommended limits
• Consider supplements that combine Vitamin K2 with Vitamin D, as they work synergistically
• Opt for products from reputable brands that conduct third-party testing to ensure quality and purity

Considerations for Vegetarians and Vegans

• Vegetarians and vegans may find it challenging to obtain sufficient MK-4 from their diet due to its prevalence in animal products
• Fermented foods like natto and certain cheeses (for vegetarians) are excellent sources of MK-7
• Vegan supplements containing MK-7 derived from natto or other plant-based fermentation processes are available

Conclusion

Understanding the differences between MK-4 and MK-7 is crucial for optimizing your health through proper Vitamin K2 intake. Both subtypes offer unique benefits, particularly for bone and cardiovascular health. While MK-4 is quickly absorbed and found in animal products, MK-7 offers sustained benefits with a longer half-life and is abundant in fermented foods.

Incorporating both forms of Vitamin K2 into your diet, either through food or supplements, can help ensure you receive the full range of health benefits. Always consult with a healthcare professional before making significant changes to your diet or starting new supplements, especially if you have underlying health conditions or are taking medications.

FAQs

Common Questions about Vitamin K2, MK-4, and MK-7

Q: What is the primary difference between MK-4 and MK-7?
A: MK-4 is found mainly in animal products and has a shorter half-life, meaning it is quickly absorbed and utilized by the body. MK-7, found in fermented foods, has a longer half-life, providing sustained benefits over time.

Q: Can I get enough Vitamin K2 from my diet alone?
A: It depends on your dietary habits. Those who consume a variety of animal products and fermented foods are more likely to get sufficient Vitamin K2. Supplements can help fill the gap if these foods are not regularly consumed.

Q: Is it safe to take Vitamin K2 supplements if I am on blood thinners?
A: People on blood thinners should consult their healthcare provider before taking Vitamin K2 supplements, as Vitamin K can interact with these medications and affect blood clotting.

Q: How do MK-4 and MK-7 work with Vitamin D?
A: Vitamin D enhances calcium absorption, while Vitamin K2 directs calcium to the bones and teeth and prevents it from depositing in arteries. Taking both together can maximize their benefits.

Q: What are the best dietary sources of MK-7 for vegetarians?
A: Fermented foods like natto and certain cheeses, such as gouda and blue cheese, are excellent sources of MK-7 for vegetarians.

References

1. Gast, G. C. M., de Roos, N. M., Sluijs, I., Bots, M. L., Beulens, J. W. J., Geleijnse, J. M., Witteman, J. C., Grobbee, D. E., Peeters, P. H. M., & van der Schouw, Y. T. (2009). A high menaquinone intake reduces the incidence of coronary heart disease. Nutrition, Metabolism and Cardiovascular Diseases, 19(7), 504-510. https://doi.org/10.1016/j.numecd.2008.10.004[↩]
2. Cassidy, A., De Vivo, I., Liu, Y., Han, J., Prescott, J., Hunter, D. J., & Rimm, E. B. (2010). Associations between diet, lifestyle factors, and telomere length in women. American Journal of Clinical Nutrition, 91(5), 1273-1280. https://doi.org/10.3945/ajcn.2009.28947[↩]