Menadione is analog of

Three compounds have the biological activity of vitamin K. Phylloquinone, the normal dietary source, found in green vegetables Menaquinones, synthesized by intestinal bacteria, with differing lengths of the side chain and Menadione and menadiol diacetate, synthetic compounds that can be metabolized to phylloquinone. Menaquinones are absorbed to some extent, but it is not clear to what extent they are biologically active as it is possible to induce signs of vitamin K deficiency simply by feeding a phylloquinone deficient diet, without inhibiting intestinal bacterial Reference: Harper; 30th edition; Page no: 554