Vitamin K2 is a relatively recently-discovered essential vitamin that contributes to heart health and bone strength. By regulating blood clotting capabilities, the growth and structure of blood vessels, and the generation of bone tissue, vitamin K2 plays a vital role in your long-term health.
Looking to use vitamin K2 to improve your heart or bone health? Check out these key benefits of vitamin K2, compiled by our researchers.
Research
Vitamin K2 benefits
1. Vitamin K2 is essential for blood coagulation
Vitamin K2 was discovered relatively late compared to other vitamins, but plays a key role in the blood clotting process (1,2), providing strong evidence for its importance in heart health.
2. Vitamin K2 could help reduce risk for heart disease
Researchers believe vitamin K2 prevents the build-up of calcium in arteries (3), which is a major risk factor in developing heart disease.
People with high levels of vitamin K2 intake have 52% lower rates of arterial calcification and are 57% less likely to die of heart disease, according to another study (4).
3. Vitamin K2 is one of two subtypes of vitamin K
Vitamin K1 is phylloquinone, and is found in leafy green plant foods (and many green drinks); vitamin K2 is menaquinone, occurring in fermented foods and animal products (5).
4. Vitamin K2 is essential for strong bones and teeth
Vitamin K2 modifies proteins to facilitate the binding of calcium, an essential mineral for strong bones and good teeth, as well as other bodily functions (6).
Vitamin K2 also activates the proteins that distribute calcium throughout the body. (7,8,9)
Researchers also believe vitamin K2 works in concert with vitamins A and D in keeping teeth strong and free of cavities. (10)
5. A vitamin K2 supplement can slow the loss of bone density in older women
This finding is according to a three-year study of post-menopausal women (11), showing that K2 reduces decreases in bone mass as women get older.
Multiple additional studies confirm the bone strengthening benefits of vitamin K2 (12,13).
However, two other large reviews concluded more evidence is needed before recommendations for supplementing with vitamin K2 to improve bone health can be endorsed (14, 15).
Vitamin K2 side effects
Vitamin K2 is extremely safe for most people. No health risks from excessive vitamin K intake have been identified, either from supplemental vitamin K2 or any form of vitamin K found in foods (16).
Talk to your doctor before taking vitamin K2 if you take warfarin or other blood clotting medication. Some heart disease experts believe that vitamin K2 could interact with warfarin and amplify its blood-thinning effects (17).
Vitamin K2 dosage
The latest nutritional guidelines suggest you need a minimum of 90-120 mcg of vitamin K2 per day. Based on new research on vitamin K2’s importance for bone and heart health, this level was significantly increased in 2020 (18).
Most studies on using vitamin K2 for bone and heart health use doses of 100 to 200 mcg of K2 per day. Based on successful studies on K2 supplementation, we used this range as a guideline when formulating our supplement rankings.
Vitamin K2 benefits FAQ
Q: Who is at risk for vitamin K2 deficiency?
A: People with a diet low in green leafy vegetables are most likely to have K2 deficiency.
Unfortunately, this category includes about one third of American adults.
Additionally, people with celiac disease and people who have had any type of gastric bypass, lap band, or other weight loss surgery are often at risk for vitamin K2 deficiency, as their ability to absorb vitamin K from their diet is impeded.
Q: What foods are rich in vitamin K2?
A: You can find vitamin K2 specifically in fermented foods, like cheese, miso, tempeh, or natto. Other forms of vitamin K are readily found in green leafy vegetables like broccoli, kale, and collard greens.
Though your body is quite capable of absorbing vitamin K in any of its forms, vitamin K that is found in vegetables is thought to be absorbed less efficiently than vitamin K2 from a supplement.
Q: What vegan foods are high in vitamin K2?
A: Unlike some other vitamins, such as vitamin B12, vegans actually have it pretty easy when it comes to getting adequate vitamin K intake overall. Vegan favorites like kale, broccoli, soy, and collard greens are all very high in vitamin K.
If you are specifically looking for vitamin K2 it can be a bit trickier, but fermented soy products like tempeh, miso, and natto are all great bets.
Q: Is vitamin K2 safe to take?
A: Yes, no upper limits on intake have been identified. A 2001 report by the Institute of Medicine noted that no adverse effects from vitamin K intake have been identified, either in humans or in animals (19).
This includes both supplemental version of vitamin K2 and dietary sources of vitamin K in all of its forms. The only caveat to this is that people who are currently taking warfarin or other blood thinners should talk to their doctor before changing their vitamin K intake levels, because warfarin’s mechanism of action may interfere with the kind of clotting that vitamin K promotes.
Related: Our best vitamin K2 picks
Summary
Vitamin K2 plays a critical role in regulating both heart health and bone strength.
Vitamin K2 works best when taken in a dosage of at least 100 mcg, and is well-tolerated as long as you don’t take blood thinners.
It’s a great supplement to add to your routine if your focus is optimizing long-term health, since both cardiovascular disease and osteoporosis become significant risks as you get older.
