Vitamin K2 MK4 and MK7: What’s the Difference?

Shopping for vitamin K2 sounds simple enough. Then you see MK4 and MK7 on supplement labels. Suddenly, buying a vitamin requires the research skills of a detective investigating a suspiciously expensive wellness trend.

So, what's the difference between vitamin K2 MK4 and MK7? Do you need one over the other, and is the more expensive bottle actually worth it? Do they behave differently?

What Is Vitamin K2, Anyway?

Vitamin K is a fat-soluble vitamin best known for its role in blood clotting. It also helps activate proteins involved in bone health and the regulation of mineralisation in soft tissues.

There are two main categories:

• Vitamin K1: Found mainly in leafy green vegetables, such as spinach, kale and broccoli.
• Vitamin K2: A group of compounds called menaquinones, found in varying amounts in fermented foods and certain animal-derived foods.

Why does K2 get so much attention?

It helps activate proteins such as osteocalcin, which is involved in bone mineralisation, and matrix Gla protein, which helps regulate mineralisation in soft tissues.

You'll often hear that vitamin K2 "directs calcium into your bones and away from your arteries". These processes involve several nutrients, proteins and biological systems, not one vitamin acting as a tiny traffic controller.

However, the evidence that it plays a role in the body doesn't automatically prove that supplements prevent osteoporosis, heart attacks or arterial calcification.

What are The Differences Between MK4 vs MK7?

When comparing vitamin K2 MK4 and MK7, the numbers aren't supplement industry code for "good" and "better". They describe differences in the compounds' chemical structures.

MK stands for menaquinone. The number refers to the number of repeating units in its side chain: four in MK4 and seven in MK7.

MK4: The Shorter-Lived Form

MK4 occurs in foods such as egg yolks, meat and liver, although the amount varies.

Its defining characteristic is its relatively short half-life in the bloodstream. In other words, it doesn't remain circulating at the same levels for as long as MK7.

What to know: MK4 has established biological functions and a history of clinical use in particular settings, but its prescription use shouldn't be treated as proof that every MK4 supplement delivers the same benefits.

MK7: The Longer-Lasting Form

MK7 is particularly associated with natto, a traditional Japanese dish made from fermented soybeans. It's an exceptionally rich dietary source, although its sticky texture and distinctive smell aren't exactly a universal crowd-pleaser.

The big difference? MK7 stays in circulation considerably longer than MK4, with a half-life measured in days rather than hours.

This makes MK7 convenient for daily supplement formulations because it can maintain circulating levels with less frequent intake.

What to know: MK7 has a longer-lasting effect on circulating vitamin K levels, but that doesn't establish it as the better option for every health outcome.

Which Form Is Better For Bone Health?

This is probably the biggest reason people shop for vitamin K2 in the first place.

Both forms are involved in pathways relevant to bone metabolism, but the evidence needs a little context.

MK4 has been studied as an osteoporosis treatment

In Japan, prescription MK4 has been used at doses much higher than those typically found in nutritional supplements. Findings from that treatment cannot automatically be applied to lower-dose products sold over the counter.

MK7 has also been studied for bone health

Some research has found improvements in markers associated with vitamin K activity, but evidence for consistent improvements in bone mineral density and reductions in fractures is less conclusive.

Here's the distinction that often gets lost on supplement websites: a change in a biological marker is not the same as proof that fewer people break their hips. Although vitamin K2 MK4 and MK7 have attracted interest for their potential role in bone health, neither is a guaranteed shortcut to stronger bones.

Does Vitamin K2 Help Your Heart?

As mentioned previously, vitamin K activates matrix Gla protein, which plays a role in regulating mineralisation in blood vessels and other soft tissues. This gives researchers a plausible reason to investigate whether supplementation could help slow arterial calcification.

Some studies have reported changes in vitamin K-dependent proteins or measures related to vascular health. However, research has not established that taking MK7 prevents heart attacks, strokes or cardiovascular deaths.

The same caution applies when evaluating vitamin K2 MK4 and MK7 for heart health: a promising biological mechanism isn't the same as proof of protection against cardiovascular disease.

If heart health is your priority, focus first on established risk factors, including blood pressure, cholesterol, smoking, diabetes and physical activity. Vitamin K2 supplements shouldn't replace proven prevention or treatment.

Can You Get MK4 And MK7 From Food?

Yes, although the two forms aren't distributed equally across the food supply.

Here's where to look:

• Egg yolks: Provide some MK4 and are easy to include in everyday meals.
• Meat and liver: Can contribute MK4, with amounts varying by food.
• Natto: An especially rich source of MK7.
• Other fermented foods: May contain different menaquinones, depending on the food and fermentation process.

Not all fermented foods contain the same amounts of vitamin K2. Eating a serving of fermented vegetables, for example, shouldn't be assumed to provide the same MK7 intake as eating natto.

For people following plant-based diets, natto can be an option if it fits their preferences. Other dietary sources depend on the particular foods eaten, and the amount of vitamin K2 available varies.

Knowing the food sources of vitamin K2 MK4 and MK7 can help you make more informed dietary choices without assuming that every fermented food provides the same nutrients.

Should You Take MK4 Or MK7?

Before adding another bottle to the kitchen cupboard, work out what you're hoping it will do.

If you want general nutritional support: Start with your diet and whether you have a specific nutritional need. The fact that a nutrient performs an important function doesn't mean everyone needs a supplement.

If you're concerned about bone health: Look at your calcium and vitamin D intake, exercise habits and individual osteoporosis risk. A healthcare professional can help determine whether assessment or treatment is appropriate.

If you're choosing based on convenience: MK7's longer time in circulation makes it a practical option for many daily formulations. That doesn't mean it has been proven to prevent more fractures than MK4.

MK4 vs MK7 At A Glance

Which One Should You Choose?

When comparing vitamin K2 MK4 and MK7, look beyond the front of the bottle. Consider why you want a supplement, what the evidence actually shows and whether it makes sense for your circumstances.

If you're looking for a convenient way to include vitamin K2 in your daily routine, Nano Singapore Vitamin K2 + D3 Complex combines 120 mcg of vitamin K2 as MK7 with 1,000 IU of vitamin D3 and black pepper extract in one capsule. Vitamin D3 helps your body absorb calcium, while vitamin K2 supports the activation of proteins involved in bone metabolism. It's a practical option to consider if you're looking to support your bone health alongside a balanced diet and healthy lifestyle.

Vitamin K2 + D3 Complex

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References

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). (2017). Dietary reference values for vitamin K. EFSA Journal, 15(5), Article 4780. https://doi.org/10.2903/j.efsa.2017.4780 

National Institutes of Health, Office of Dietary Supplements. (n.d.). Vitamin K: Fact sheet for consumers. https://ods.od.nih.gov/factsheets/VitaminK-Consumer/ 

National Institutes of Health, Office of Dietary Supplements. (n.d.). Vitamin K: Fact sheet for health professionals. https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/ 

Medical disclaimer: This article is for general educational purposes and does not replace individual medical advice. Consult a healthcare professional before starting supplements or changing prescribed treatment.