Explain Vitamin K as an essential fat soluble micronutrient?

Vitamin K is an essential fat-soluble micronutrient the only unequivocal role in health is in the maintenance of normal coagulation. Vitamin K is the family name for a series of fat-soluble compounds which have a  common 2-methyl- 1 ,4 naphthoquinone nucleus but differ in the structures of a side chain at the 3-position. They are synthesized by plants and bacteria. In plants, the only important molecular form is phylloquinone (vitamin K1), which has a phytyl side chain. Bacteria synthesize a family of compounds called menaquinones (vitamin K₂), which have side chains based on repeating unsaturated 5-carbon (prenyl) units. Look up Unit 3 in the Nutritional Biochemistry Course to study the structure of these two compounds.

Menaquinones are designated menaquinone-n. (MK-n) according to the number (n) of prenyl units. The compound 2-methyl-1,4-naphthpquinone (common name menadione) may be regarded as a provitamin because vertebrates can convert it to   MK-4 by adding a 4-prenyl side chain at the 3-position.