Naturally, vitamin K exists in two bioactive forms mainly phylloquinone (vitamin K1) and menaquinones (vitamin K2). Phylloquinone is mostly found in green leafy vegetables such as kale, spinach, broccoli, and vegetable oils. However, menaquinones abundantly occurs in fermented vegetable products as menaquinones‐7 (MK‐7) and in animal‐based products as menaquinone‐4 (MK‐4). Diverse concentrations of menaquinones are present in various dietary sources such as fermented pulses and milk‐based products, cheese, meat, and animal organs. Presently, MK‐7 and MK‐4 contribute about 24 and 7%, respectively, of the total vitamin K dietary intake in the population consuming fermented products regularly. However, about 10% of menaquinones are pooled in the liver out of total intake of vitamin K. Conclusively, fermented soybean products and fermented milk‐based products such as cheese and soured milk contain ample amount of MK‐7, whereas animal organs, meat, fish, and egg contain appreciable amount of MK‐4.
Part of the book: Vitamin K2