Vitamin K2, also known as menaquinone, is an important class of fat-soluble vitamins and one of the indispensable and important vitamins in the human body. Because of its very small content in food, it is known as "platinum vitamin". According to different side chains, vitamin K2 can be divided into 14 types. Currently commercialized vitamin K2 is MK-4 and MK-7. Commercial vitamin K2 with good functionality usually refers to MK7. MK7 has two structures of trans and cis. , where the trans structure is functional and the cis structure is not.It has the function of promoting bone health and preventing vascular calcification