Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins, mostly required for blood coagulation but also involved in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone (3-)derivatives. This group of vitamins includes two natural vitamers: vitamin K1 and vitamin K2. Vitamin K1 is also known as vitamin Kj, phylloquinone or phytomenadione (also called phytonadione). Plants synthesize vitamin K1 while bacteria can produce a range of vitamin K2 forms, including the conversion of K1 to K2 by bacteria in the small intestines...