Vitamin K1 (phylloquinone), the major dietary form of vitamin K, mainly can be found in green leafy vegetables, such as kale, parsley and broccoli and some vegetable oils (soybean, cottonseed, canola and olive).
Vitamin K2 forms (menaquinones) can be found mainly in dairy products. In Asia, a fermented soy product called natto is very popular. It remains unclear how exactly the bacteria that normally colonize the digestive tract (‘large intestine’) and synthesize vitamin K2 contribute to the human vitamin K requirement (37).
In many countries, vitamin K1 is available without a prescription in multivitamin and other supplements. Multivitamins generally contain 10–to 25 micrograms (mcg) of vitamin K while vitamin K or "bone" supplements may contain 100–120 micrograms (mcg) of vitamin K (38).
Authored by Dr Peter Engel in 2010, reviewed and updated by Dr Szabolcs Peter on 18.06.2017