Vitamin K2

“Vitamin K,” the generic name for a family of compounds with a common chemical structure of 2-methyl-1,4-naphthoquinone, is a fat-soluble vitamin that is naturally present in some foods and is available as a dietary supplement. These compounds include phylloquinone (vitamin K1) and a series of menaquinones (vitamin K2). Menaquinones have unsaturated isoprenyl side chains and are designated as MK-4 through MK-13, based on the length of their side chain. MK-4, MK-7, and MK-9 are the most well-studied menaquinones.