What is Vitamin K-2? What is the Best Form of Vitamin K-2 to Take?

What is Vitamin K-2? What is the Best Form of Vitamin K-2 to Take?

Sure, you’ve heard of vitamins A, B and C, but have you heard of vitamin K? The first thing to know about vitamin K is that it’s not just one vitamin. Vitamin K is a family of fat-soluble vitamins including Vitamin K-2, which has the most research.1

Vitamin K is essential to overall health because it supports nearly all major systems and directly or indirectly participates in hundreds of biological processes in the human body.1 Because of this broad range of activity, vitamin K supports many key areas of health including the heart, bones and blood clotting.2*

One of the key pathways vitamin K influences is the regulation of calcium, which explains in part how it supports heart health.3 A 2019 analysis of 21 studies found that higher dietary vitamin K consumption supported heart health more than individuals who ate minimal vitamin K-containing foods.4*

Vitamin K also supports osteocalcin production, which is an important protein for bone health. According to a 2022 analysis of 16 different randomized controlled trials, vitamin K-2 supplementation positively supported bone mineral density in postmenopausal women.5*

Sources of K

Vitamin K-2 is a compound known as menaquinone (MK), there are several menaquinones which are numbered based on their length (e.g., MK-7).6 Menaquinones are primarily found in modest amounts in various animal-based and fermented foods such as natto, which is a traditional Japanese food made from fermented soy.6 Bacteria in the gut also make the longer chain menaquinones, such as MK-7.7

Best Vitamin K Supplement

Even though vitamin K is a fat-soluble vitamin (which means it should stay in circulation longer than a water-soluble vitamin), it is rapidly metabolized and not well absorbed.6 This means many people may not be getting enough of this valuable vitamin from food alone. It also means that some dietary supplements may be better absorbed than others.*

Research shows that vitamin K-2, in particular the MK-7 vitamin, is more readily absorbed than vitamin K-1.7 If you are looking for the best vitamin K supplement, be sure the label indicates it is vitamin K-2 as menaquinone-7 (MK-7) from natto (soy), which has the highest concentration of MK-7. Our K-2 MK-7 comes in an instant dissolve tablet for those who want easy, on-the-go support.*

Learn more about why strong bones are good for overall health, including the brain. For more tips on nutrition, mind & body health, and taking care of your family follow us on Facebook @kalvits and Instagram at @kalvitamins!


*These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.



  1.  Yan Q, Zhang T, O'Connor C, et al. The biological responses of vitamin K2: A comprehensive review. Food Sci Nutr. 2023;11(4):1634-1656. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10084986/?report=reader
  2.  DiNicolantonio JJ, Bhutani J, O’Keefe JH. The health benefits of vitamin K. Open Heart. 2015;2. https://openheart.bmj.com/content/2/1/e000300
  3.  Hariri E, Kassis N, Iskandar J, et al. Vitamin K2—a neglected player in cardiovascular health: a narrative review. Open Heart. 2021;8. https://openheart.bmj.com/content/8/2/e001715
  4.  Chen H, Sheng L, Zhang Y, 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. https://pubmed.ncbi.nlm.nih.gov/31119401/
  5. Ma ML, Ma ZJ, He YL, et al. Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: A systematic review and meta-analysis of randomized controlled trials. Front Public Health. 2022;10:979649. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9403798/?report=reader
  6.  National Institutes of Health Office of Dietary Supplements. Vitamin K Fact Sheet for Health Professionals. 2021;Mar 29. https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
  7.  Jadhav N, Ajgaonkar S, Saha P, et al. Molecular Pathways and Roles for Vitamin K2-7 as a Health-Beneficial Nutraceutical: Challenges and Opportunities. Front Pharmacol. 2022;13:896920. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9237441/?report=reader
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