Where is menaquinone found? Your guide to Vitamin K2 sources

January 13, 2026 •

1 min read

Menaquinone, also known as vitamin K2, is primarily synthesized by bacteria, and some of its most potent forms are found in specific fermented foods. This fat-soluble vitamin plays a crucial role in regulating calcium deposition and is gaining recognition for its benefits beyond blood clotting.

Quick Summary

Menaquinone (Vitamin K2) is found in fermented foods, dairy, and animal products, with its specific forms (MK-4, MK-7, MK-8, MK-9) varying by source. Gut bacteria also produce it, though dietary intake is the primary functional source.

Key Points

Fermented foods contain high levels of menaquinone: Natto, a fermented soybean dish, is the richest known food source of menaquinone, particularly MK-7.
Animal products provide menaquinone-4: Meat, egg yolks, and liver are reliable dietary sources of the short-chain menaquinone, MK-4.
Gut bacteria produce menaquinones, but absorption is limited: While bacteria in the human gut synthesize menaquinones, dietary intake provides the most functional vitamin K2.
Cheese is a significant source of multiple menaquinone types: Aged and hard cheeses, like Gouda and Edam, are rich in various long-chain menaquinones, including MK-8 and MK-9.
Menaquinone supports bone and heart health: By activating specific proteins, menaquinone helps regulate calcium, promoting bone health and preventing arterial calcification.
Supplementation is an option for increased intake: Vitamin K2 supplements, especially those containing MK-7, are widely available for those who need to boost their menaquinone levels.

Sources of Menaquinone

Menaquinones are found in various foods, with fermented options like natto being particularly rich in MK-7. Aged and hard cheeses also provide different forms, including MK-8 and MK-9. Animal products, such as organ meats, egg yolks, and certain meats like chicken, are sources of the MK-4 form. While gut bacteria do produce some menaquinones, absorption can be limited, making dietary sources more important for overall intake.

Comparison of Menaquinone Sources and Types

Different food sources contain varying types and amounts of menaquinone. For a detailed comparison of common sources like natto, cheeses, and animal products, including their primary menaquinone types and typical concentrations, please refer to {Link: consensus.app https://consensus.app/search/top-foods-high-in-vitamin-k2-write-as-an-article-w/5ogh726pRA6WCkZolROusw/}.

Supplements

Supplements can be used to increase menaquinone intake, commonly offering MK-4 and MK-7 forms. MK-7 is often favored for its longer half-life in the body. Consultation with a healthcare provider is advised before starting supplements. More information is available from the {Link: National Institutes of Health Fact Sheet for Health Professionals https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/}.

Conclusion

Menaquinone sources are diverse, with MK-4 primarily in animal products and long-chain forms like MK-7 abundant in fermented foods. Dietary intake is essential for functional menaquinone, supporting bone and heart health. A varied diet incorporating these sources can help ensure adequate levels.

Frequently Asked Questions

Menaquinone (K2) is primarily found in animal and fermented foods and produced by bacteria, while phylloquinone (K1) is plant-based and abundant in leafy green vegetables. K2 is also absorbed more readily and has a longer half-life in the body than K1.

Natto, a Japanese dish made from fermented soybeans, is the richest known food source of menaquinone, specifically MK-7.

While gut microbiota produce some menaquinone, the amount is often insufficient to meet the body's needs due to poor absorption from the large intestine. Dietary sources are the most reliable way to obtain functional menaquinone.

No, menaquinones exist in various forms, designated MK-4 through MK-13, with different side chain lengths. These different forms are found in different foods and may have varying bioactivity and absorption rates.

Menaquinone is crucial for activating proteins that help regulate calcium. It directs calcium to your bones and teeth while preventing it from being deposited in soft tissues like arteries, thereby supporting bone and heart health.

Yes, especially in fermented dairy products like aged and hard cheeses (e.g., Gouda, Edam) and some full-fat milks. The type and amount can vary based on the fermentation process and the bacteria used.

The best way is through a balanced diet including both fermented foods (like natto and aged cheeses) and animal products (like eggs and liver). For those with dietary restrictions or deficiencies, supplements containing MK-7 are a highly bioavailable option.