Vitamin K and hemostasis

Abstract

Vitamin K is necessary for the synthesis of the proteins that help control bleeding (clotting factors) and thus for the normal clotting of blood. Newborns are prone to vitamin K deficiency because only small amounts of vitamin K cross the placenta and because, during the first few days after birth, their intestine does not contain bacteria to produce vitamin K. The deficiency can cause hemorrhagic disease of the newborn, characterized by a tendency to bleed. A vitamin K injection in the muscle is recommended for all newborns to reduce the risk of bleeding within the brain after delivery.