Vitamin K (Kephton) has blood coagulation action and is important for coagulation factors, matrix-Gla protein, and osteocalcin.

Vitamin K plays an important role in nervous system. Vitamin K facilitates the bioactivation of protein Gas6 and protein S, ligands of the TAM family (Tyro3, Axl and Mer) receptor tyrosine kinases. In the brain, vitamin K is involved in the synthesis of sphingolipids [3].

Vitamin K supplementation is beneficial in improving insulin sensitivity and glucose tolerance, reducing the risk of type 2 diabetes, and preventing insulin resistance. The recommended intake of adequate vitamin K is 90 micrograms per day for women and 120 micrograms per day for men [2]. Vitamin K deficiency leads to an increase in hypocarboxylated osteocalcin, a decrease in bone mineral density, and an increased probability of fracture. Vitamin K supplementation reduces undercarboxylated osteocalcin and improves bone turnover curves [4].