There is a small amount of vitamin K2 in colon, which is synthesized by intestinal flora. Vitamin K2 is mainly found in animal products, such as meat, dairy products and eggs, as well as fermented foods such as cheese, yoghurt and natto, which are traditional fermented soybeans in Japan. (Note: vitamin K2 only exists in "real" cheese that is unprocessed cheese, or "cheese" food. Food processing removes vitamins, and some other chemical "cheeses" don't contain nutrients like vitamin K2 at all from the beginning.)

Every 100g of cultured cheese like Gouda can provide up to 50mcg of menaquinone-7 (vitamin K2). However, the most abundant source of natural vitamin K2 is the traditional Japanese natto, which provides a large number of unique natural vitamin K2 (long-chain menaquinone-7, MK-7).

Generally speaking, the typical Western diet does not contain sufficient vitamin K2 to fully activate MGP, which means that about 30% of the proteins that need to be activated by vitamin K2 remain inactive. Because of this defect, it is recommended to use vitamin K2 supplements.