Vitamin K1 and K2 share a name and a basic job, but they come from different foods and behave differently once you eat them. Here's a clear breakdown, without the hype.
Written by Vita Globe Editorial Team | Reviewed against NIH guidance and peer-reviewed research
What's the difference between vitamin K1 and K2?
Vitamin K1 (phylloquinone) comes mainly from leafy green vegetables. Vitamin K2 (menaquinones, such as MK-4 and MK-7) comes mostly from bacteria, fermented foods and animal foods[1]. Both activate the same kinds of proteins, including clotting factors and bone proteins[1]. The key difference is how they're handled: long-chain K2 like MK-7 stays in the blood much longer than K1[2], which may make it more available to tissues outside the liver.
Caveat: Official intake recommendations don't separate K1 and K2. The Adequate Intake applies to vitamin K overall[1].
Sources: NIH ODS · Schurgers et al., 2007 · Verified 2026-09-27
In this article
Where do K1 and K2 come from?
K1 (phylloquinone) is made by plants. It's the main form in most diets, with big amounts in foods like collard greens, spinach and broccoli[1].
K2 (menaquinones) is a group of compounds named by the length of their side chain, from MK-4 to MK-13[1]. Most are made by bacteria, so they show up in fermented foods like natto and many cheeses[3]. MK-4 is different: your body makes it from K1, and it's found in animal foods like chicken, eggs and dairy[1].
| Vitamin K1 | Vitamin K2 | |
|---|---|---|
| Chemical name | Phylloquinone | Menaquinones (MK-4 to MK-13) |
| Main sources | Leafy greens, some vegetable oils | Natto, cheese, meat, eggs, dairy |
| Made by | Plants | Mostly bacteria (MK-4 is made in the body) |
| Time in blood | Short | MK-7: much longer |
Do K1 and K2 do the same job?
At the core, yes. Both help an enzyme activate vitamin K-dependent proteins: clotting factors, osteocalcin in bone and matrix Gla protein in blood vessels[1].
The difference is where they tend to end up. Much of the K1 you eat is used by the liver, where clotting factors are made. Researchers think longer-lasting forms like MK-7 are more available to other tissues such as bone and blood vessels[2][4]. That's the main reason K2 gets attention for bone and heart research.
Which is better absorbed?
In a head-to-head study, MK-7 had a much longer half-life than K1 and built up to higher, steadier levels in the blood with daily dosing[2]. Another study found MK-7 was well absorbed and detectable in the blood for up to 48 hours, while nutritional doses of MK-4 weren't detectable at all[4].
So "K2" isn't one thing. MK-7 and MK-4 behave very differently. See MK-7 vs. MK-4 for more.
What does the research say about each for health?
For clotting, K1 is the well-established form. For bone and heart health, research has focused more on K2.
In the Rotterdam Study, people who got more menaquinones (K2) from their diet had a lower risk of dying from coronary heart disease, while K1 intake showed no such link[5]. That's an observational finding, not proof. A pooled analysis later found both higher K1 and higher K2 intakes associated with a modestly lower risk of coronary heart disease[6].
The honest summary
- K1 and K2 do the same basic job but come from different foods.
- MK-7 (a type of K2) stays in the body much longer than K1.
- K2's bone and heart links are promising but not proven.
- You don't need to choose one: a varied diet gives you both.
Should you take K1 or K2?
Most people get plenty of K1 by eating vegetables. K2 is harder to get unless you eat natto or lots of cheese, which is one reason many bone-support supplements use K2.
Whichever you choose, the same rule applies: if you take warfarin, both K1 and K2 affect how the drug works, so talk to your doctor before making changes[1]. More in vitamin K2 and blood thinners.
Our option
Vita Globe Vitamin K2 Gummies
Our Vitamin K2 Gummies focus on K2, the form that's harder to get from a typical diet. They're raspberry-flavored, with a suggested use of 2 gummies once daily, and they're vegan-friendly, gluten-free and non-GMO, made without artificial colors or flavors. Like every Vita Globe product, they're tested by an independent third-party lab.
Frequently asked questions
Is vitamin K2 better than K1?
Not better overall, just different. K1 is well established for clotting. K2, especially MK-7, lasts longer in the blood[2], which is why it's studied for bone and heart health.
Can your body convert K1 into K2?
Yes, partly. Your body makes MK-4, a form of K2, from K1[1]. It doesn't make MK-7, which comes from bacteria.
Do leafy greens have vitamin K2?
Leafy greens are rich in K1, not K2[1]. K2 is found in fermented foods, cheese, eggs and meat.
Does warfarin affect both K1 and K2?
Yes. Warfarin works by interfering with vitamin K's role in clotting, so changes in either form can affect it[1][7].
Sources
- Office of Dietary Supplements, National Institutes of Health. Vitamin K: Fact Sheet for Health Professionals. Updated March 29, 2021. ods.od.nih.gov
- Schurgers LJ, Teunissen KJF, Hamulyák K, Knapen MHJ, Vik H, Vermeer C. Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood. 2007;109(8):3279-3283. doi:10.1182/blood-2006-08-040709
- Walther B, Karl JP, Booth SL, Boyaval P. Menaquinones, bacteria, and the food supply: the relevance of dairy and fermented food products to vitamin K requirements. Adv Nutr. 2013;4(4):463-473. doi:10.3945/an.113.003855
- Sato T, Schurgers LJ, Uenishi K. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J. 2012;11:93. doi:10.1186/1475-2891-11-93
- Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004;134(11):3100-3105. doi:10.1093/jn/134.11.3100
- Chen HG, Sheng LT, Zhang YB, et al. Association of vitamin K with cardiovascular events and all-cause mortality: a systematic review and meta-analysis. Eur J Nutr. 2019;58(6):2191-2205. doi:10.1007/s00394-019-01998-3
- Holbrook AM, Pereira JA, Labiris R, et al. Systematic overview of warfarin and its drug and food interactions. Arch Intern Med. 2005;165(10):1095-1106. doi:10.1001/archinte.165.10.1095
About the Vita Globe Editorial Team
The Vita Globe Editorial Team researches and writes our wellness content, working from peer-reviewed research, systematic reviews and guidance from bodies such as the NIH and the FDA. We cite our sources inline and update articles when the evidence changes.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for medical advice. Talk to your healthcare provider before starting any new supplement, particularly if you are pregnant, nursing, taking medication, or caring for a child.
