What is vitamin k2?
Significant research shows vitamin K2 from natural fermentation – especially its key long chain isomer MK-7 – is essential for bone- and cardiovascular-health support.
The power of vitamin k2
Besides its proven role in bone and cardiovascular health, new research is revealing how K2 delivers other health benefits.
In fact, vitamin K2 may be the missing link between diet and several chronic conditions. And the only vitamin K2 as MK-7 confirmed with ironclad clinical validation to deliver improved health is MenaQ7®.
What is vitamin k2? What role does it play in human health?
Vitamin K2 is a dietary vitamin in the vitamin K family, a group of fat-soluble compounds that support blood clotting, calcium metabolism, and antioxidant activity. Among these forms, long-chain menaquinone-7 (MK-7), especially when produced by natural fermentation, stands out for its benefits to bone and cardiovascular health because it remains available in the body longer than other forms.
Like vitamin K1 (phylloquinones), vitamin K2 shares the same methylated naphthoquinone ring, but its aliphatic side chains change absorption, transport, tissue distribution, and bioavailability. Vitamin K2 includes multiple menaquinone forms designated MK-4 through MK-13 based on side-chain structure. Within the vitamin K family, vitamin K1 is the main counterpart, and among K2 forms, vitamin K2 as long-chain menaquinone-7 (MK-7) shows higher and more specifically effective activity in humans than vitamin K2 as MK-4.
The higher efficacy of MK-7 is attributed to its better bioavailability and longer half-life compared to other homologs. Both vitamin K2 as MK-4 and MK-7 are nearly completely absorbed, with peak serum concentration at 2 hours for MK-4 and 4 hours for MK-7 after intake. However, MK-4 quickly disappears from the circulation, whereas MK-7 can accumulate in the bloodstream (remaining in the body for approximately 72 hours).
For maximum effect in the body, MK-7 is the optimal source of vitamin K. For nutraceutical, pharmaceutical, and functional food & beverage brands developing science-backed products, this matters because low dietary vitamin K intake is common, and K2 is critical for directing calcium to bones rather than arteries. This article explains vitamin K2 sources, deficiency concerns, clinical evidence behind MenaQ7®, and how validated K2 solutions can support children, active adults, and women.
Vitamin K2 simultaneously supports bone and heart health. But did you know that research also points to an important link between K2 and kidney health?
How does vitamin k2 work?
Decades of research have shown that vitamin K2 as MK-7 is essential for the function of several calcium-binding proteins involved in maintaining the normal structure of the osteoarticular system and teeth, the arterial wall, and for the regulation of cell growth. It also plays a critical role in bone metabolism and bone mineralization.
Vitamin K2 “makes calcium work” through its ability to activate specific K-dependent proteins already present in the body:
- Osteocalcin is the protein responsible for binding calcium ions to the bone mineral matrix, thereby strengthening bones.
- Matrix Gla Protein (MGP) is the most potent modulator of vascular calcification known today, and vitamin K2 is involved in the activation of Matrix Gla Protein. Activated MGP helps stop vascular calcification, and the amount of arterial calcification is an indicator of one’s cardiovascular health.
When the body has sufficient vitamin K2, calcium is directed to where it is needed and kept away from where it is not. However, inadequate vitamin K2 may result in what is known as the “Calcium Paradox.” This is where the bones receive too little calcium (leaving them weak and brittle) while excess calcium deposits in the arteries and blood vessels (making them stiff and inelastic). Low vitamin K status is linked to a higher risk of calcium being misdirected away from bones and into arteries.
Vitamin K2 deficiency impairs bone strength and mineral density, contributing to bone loss and raising concern about fractures. Calcification increases the stiffness and fragility of vessels, impeding healthy blood flow to and from the heart.
Claiming that an ingredient is clinically validated requires an extraordinary level of investment and dedication – a journey that the team behind MenaQ7® Vitamin K2 as MK-7 has undertaken with unwavering commitment.
Explore the story behind MenaQ7® and discover the unparalleled commitment that has shaped this clinically validated vitamin K2 solution.
Vitamin k2 deficiency
Vitamin K1 comes mainly from plant sources, while vitamin K2 is supplied by animal products and fermented foods such as butter from grass-fed animals, whole milk, mature cheeses, curd, egg yolks, liver, sauerkraut, and the traditional Japanese fermented soybean dish “natto.” In terms of food composition, grass-fed butter contains more K2 than grain-fed butter. MK-4 is found in chicken and beef; beef liver provides over 11 micrograms per 100 grams, egg yolks can range from 67 to 192 micrograms, and sauerkraut provides about 2.75 micrograms per half-cup.
The amount of vitamin K2 (MK-7) required for optimal carboxylation is significantly higher than what is available in the body. Unlike other fat-soluble nutrients, vitamin K2 is not stored in the body.
While K2 deficiency is often subclinical in many healthy populations. It is present in most healthy adults and children consuming Western diets, and variable data on dietary vitamin k intake can make estimates harder because vitamin K2 values differ across sources.
Adequate vitamin K2 is virtually non-existent in today’s food supply. Unfortunately, the food industry has not fortified many foods—such as breakfast cereals—with vitamin K2 the way it has with folic acid and calcium. While vitamin k-rich foods matter, many people still do not reach adequate amounts through dietary intake alone. For now, supplementation remains the best option.
Vitamin K2 quick facts
- Vitamin K2 is a fat-soluble nutrient.
- Vitamin K2 can render special proteins (vitamin K-dependent proteins) functional by adding carboxyl (-cooh) groups.
- Vitamin K2 is needed for normal blood coagulation.
- Vitamin K2 is produced via bacterial fermentation, which gives fermented foods like cheese and the Japanese dish natto (fermented soybeans) high Vitamin K2 content.
- Bacterial production of vitamin K2 also occurs in the large intestine, though that does not necessarily ensure sufficient vitamin K status.
- Vitamin K2 is also involved in bone formation and repair, and helps maintain bones.
- Vitamin K2 is associated with reduced risk for heart disease, fits within a heart-healthy diet, and is associated with a lower risk of hip fractures.
- Vitamin K2 has been shown to inhibit calcium deposits (calcification) in blood vessels and has beneficial effects on arterial flexibility.
- In the last decade, several studies have highlighted the benefits of vitamin K2, specifically menaquinone-7, at every stage of life.
Vitamin K2 as MK-7 benefits every stage of life
Although vitamin K has been known for decades, dietary recommendations have largely focused on the nominal amount of K1 required for healthy blood clotting; meanwhile, vitamin K2 intake guidance has received far less attention despite its role in maintaining healthy bones and arteries at all stages of life. It is now accepted that adequate intake of vitamin K2 is essential for healthy bones and may help lower the risk of cardiovascular disease by limiting vascular damage. But almost all of us are potentially deficient in vitamin K2 due to poor dietary habits, and current evidence supports the importance of consistent intake across the lifespan, even as optimal amounts are still being refined.
Children and vitamin K2
Vitamin K2 status in children helps create strong, healthy bones. Research shows that children have higher levels of inactive osteocalcin, a marker of poor vitamin K status, than adults. Without adequate vitamin K2, specifically menaquinone-7 (MK-7), calcium cannot be effectively utilized by the body to build healthy, strong bones; accordingly, children and adolescents may benefit most from vitamin K2 supplementation.
Sport & active life
Humans attain 90% of peak bone mass at age 18 for girls and 19 for boys. However, by the time we reach age 40 or so, we slowly begin to lose bone mass. Without adequate vitamin K2 intake, a significant portion of osteocalcin will stay inactive and unable to bind calcium to ensure bones are at their strongest to carry us forward. Vitamin K2 might also benefit active individuals by supporting joint, heart, and brain health.
Women wellness
Women’s health needs change significantly during menopause due to hormonal fluctuations. Older adults, especially elderly women after menopause, face an increased risk of osteoporosis and cardiovascular changes. Daily supplementation with vitamin K2 is particularly important during this phase. A 2022 meta-analysis found K2 improved bone mineralization and bone strength in women. It is essential for maintaining cardiovascular and bone health as it reduces risks of heart disease and osteoporosis. By supporting proper calcium utilization, blood vessel integrity, protection against bone loss, and a lower risk of bone fractures, vitamin K2 helps women maintain vitality and overall well-being during — and after — menopause.
Healthy aging
An increasing number of age-associated diseases are related to vitamin K2 insufficiency, as older adults face a higher risk of adverse age-related bone and vascular changes due to the body’s improper use of calcium. This has been shown in clinical studies of compromised heart and bone health in healthy older men and women, and in one study of 243 healthy subjects, which found reduced arterial stiffness among participants supplementing with MK-7. Vitamin K2’s cardiovascular mechanism is now also being linked to potential brain health benefits.
How can vitamin k2 be obtained
Ideally, we would obtain all of our nutrients naturally from our diets. While dietary vitamin K remains important for good health, K2 can be difficult to obtain in adequate amounts from modern diets alone. However, if that is not possible, vitamin K supplementation is an option through supplements produced as close to nature as possible. A high intake of vitamin K2 has been associated with a lower risk of heart disease, with each additional 10 micrograms daily linked to a 9% reduction.
There has been a lot of talk about K2 produced via “organic synthesis,” but the term is often misleading. Gnosis by Lesaffre offers a position paper that explains the differences between natural fermentation and synthesis, the specificities of K2 obtained through a natural fermentation-based process, and what should be considered when selecting a vitamin K2, such as MK-7, produced by synthesis.
What is Natto? A look at fermented foods
While natto is less common in the West, in Japan, it is very popular and frequently consumed for its nutritional value and health benefits. Natto is one of the most concentrated vitamin K-rich foods, specifically in MK-7. One 3.5-oz. serving of natto contains 1,103.4 micrograms of MK-7.
That is a massive amount compared to egg yolks (15.5 micrograms) and whole milk (1.0 micrograms), and natto stands out further because Western diets generally contain fewer concentrated K2 sources; egg yolks and milk contain the less effective form of vitamin K2 as MK-4.
MenaQ7® is manufactured through fermentation using a strain of Bacillus subtilis, which is derived from natto. Typically, smaller soybeans are preferred so that the fermentation process can reach the center to increase their overall health benefits. Here’s how MenaQ7® is produced:
- First, the beans are washed and soaked for 12 to 20 hours to increase their size. Second, the soybeans are steamed for roughly six hours.
- The beans are then mixed with the special Bacillus subtilis bacteria and special care is taken to make sure no impurities or other bacteria are introduced.
- The mixture is then fermented at 104 F (40 C) for up to 24 hours. Afterwards it is cooled and aged in refrigeration for up to one week.
