Vitamin K | ... Free Vitamin Encyclopedia.

Vitamin K

Vitamin K helps the body make proteins for bones and tissues, and it makes proteins for blood clotting. A deficiency in vitamin K can lead to excessive bleeding.[1]

But where do we get vitamin K? What else can it do for us?

Are some forms better than others – and can we get enough from diet alone?

Where do we get vitamin K?

There are two main forms of vitamin K: vitamin K1 and vitamin K2.

We get vitamin K1 from green leafy vegetables like spinach, lettuce, kale, Brussels sprouts and broccoli. Sources of vitamin K2 include fermented foods like ripe cheese, yogurt and a fermented soy called natto, which is a staple in some parts of Japan.

Vitamin K2 has been found to be much more beneficial.[2]

Why is vitamin K2 important?

Foods like natto are a staple in the Japanese diet, but they aren’t in the American diet. However, vitamin K2 helps our bodies in a lot of ways.

Bone Health

Vitamin K2 is required for the hormone – osteocalcin – that regulates the mineralization of bones and teeth.[3] It gives osteocalcin the ability to move calcium into bones. Without enough vitamin K2, calcium can settle in our arteries and joints.

Researchers have found that vitamin K increases calcium absorption,[4] leading to a decrease in bone loss.[5] It’s also been shown to reduce the risk of fractures and prevent bone loss.[6]

Heart Health

Since vitamin K plays a role in blood clotting, it makes sense that is also has an impact on our arteries and heart health. Vitamin K is required by matrix gla-protein, a protein that inhibits vascular calcification.[7]

Researchers have found that high levels of vitamin K2 are linked with a reduction in coronary calcification.[8] The Rotterdam Study also found that high intakes of vitamin K2 can significantly reduce sever aortic calcification and deaths from coronary heart disease.[9] Researchers also found that supplementing with vitamin K2 can reduce existing arterial calcification by 37% in 6 weeks.[10]


Researchers followed over 38,000 people for a decade and found that higher intakes of vitamin K were linked to a lower risk of type 2 diabetes.[11]Another study found that supplementing with vitamin K2 can improve response in one week.[12]


Vitamin K may play a role in brain physiology and Alzheimer’s. Researchers found that Alzheimer’s patients had lower intakes of vitamin K.[13]


In Leukemia there are too many white blood cells in the blood or bones. Researchers found that vitamin K2 can lead to the breakdown or even death of leukemia cells.[14]


A deficiency in vitamin K can cause excessive uterine bleeding.[15] In China, a standard treatment for menstrual pain is an injection of vitamin K.[16]

How To Choose A Supplement

Vitamin K is a vital supporting ingredient for Calcium, so ideally Vitamin K will be found in your Calcium Supplement. As mentioned above, the ideal form is K2, also known as menaquinone-7 or mk-7. In studies, the effective dose for heart health has been 250mcg per day.[17]

For more detailed information regarding our calcium supplement recommendation, click here.


  1. ^ Wikipedia contributors. “Vitamin K.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 10 Aug. 2016. Web. 19 Aug. 2016
  2. ^ Sato, Toshiro, Leon J. Schurgers, and Kazuhiro Uenishi. “Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women.” Nutrition journal 11.1 (2012): 1.
  3. ^ Hauschka, PETER V., et al. “Osteocalcin and matrix Gla protein: vitamin K-dependent proteins in bone.” Physiological reviews 69.3 (1989): 990-1047.
  4. ^ Knapen, Marjo HJ, Karly Hamulyák, and Cees Vermeer. “The effect of vitamin K supplementation on circulating osteocalcin (bone Gla protein) and urinary calcium excretion.” Annals of internal medicine 111.12 (1989): 1001-1005.
  5. ^ Braam, L. A. J. L. M., et al. “Vitamin K1 supplementation retards bone loss in postmenopausal women between 50 and 60 years of age.” Calcified Tissue International 73.1 (2003): 21-26.
  6. ^ Zittermann, Armin. “Effects of vitamin K on calcium and bone metabolism.” Current Opinion in Clinical Nutrition & Metabolic Care 4.6 (2001): 483-487.
  7. ^ Schurgers, L. J., et al. “Post‐translational modifications regulate matrix Gla protein function: importance for inhibition of vascular smooth muscle cell calcification.” Journal of Thrombosis and Haemostasis 5.12 (2007): 2503-2511.
  8. ^ Beulens, Joline WJ, et al. “High dietary menaquinone intake is associated with reduced coronary calcification.” Atherosclerosis 203.2 (2009): 489-493.
  9. ^ Geleijnse, Johanna M., et al. “Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study.” The Journal of nutrition 134.11 (2004): 3100-3105.
  10. ^ Schurgers, Leon J., et al. “Regression of induced medial elastocalcinosis by high intake of vitamin K in rats.” Blood 109.7 (2007): 2823-2831.
  11. ^ Beulens, Joline WJ, et al. “Dietary phylloquinone and menaquinones intakes and risk of type 2 diabetes.” Diabetes care 33.8 (2010): 1699-1705.
  12. ^ Sakamoto, N., et al. “Possible effects of one week vitamin K (menaquinone-4) tablets intake on glucose tolerance in healthy young male volunteers with different descarboxy prothrombin levels.” Clinical Nutrition 19.4 (2000): 259-263.
  13. ^ Presse, Nancy, et al. “Low vitamin K intakes in community-dwelling elders at an early stage of Alzheimer’s disease.” Journal of the American Dietetic Association 108.12 (2008): 2095-2099.
  14. ^ Yokoyama, Tomohisa, et al. “Vitamin K2 induces autophagy and apoptosis simultaneously in leukemia cells.” Autophagy 4.5 (2008): 629-640.
  15. ^ Lusher, Jeanne M. “Systemic causes of excessive uterine bleeding.” Seminars in hematology. Vol. 36. No. 3 Suppl 4. 1999.
  16. ^ Wang, Li, et al. “Vitamin K acupuncture pint injection for severe primary dysmenorrhea: an international pilot study.” MedGenMed 6.4 (2004): 45.
  17. ^ Schurgers, Leon J., et al. “Regression of induced medial elastocalcinosis by high intake of vitamin K in rats.” Blood 109.7 (2007): 2823-2831.