Final answer:
Normal coagulation involves the process of clot retraction and fibrinolysis, where vitamin K is essential for the synthesis of certain clotting factors involved in these stages.
Step-by-step explanation:
Normal coagulation requires vitamin K and also involves clot retraction (tightening of the clot) and fibrinolysis (dissolution of the clot). Coagulation involves a complex cascade of events, starting with an injury to a blood vessel which initiates hemostasis. In this process, clots form due to the action of platelets and clotting factors, many of which require vitamin K. During clot retraction, contractile proteins in the platelets pull on the fibrin threads, tightening the formed clot. Following the cessation of bleeding and beginning of healing, fibrinolysis occurs, where the clot is gradually dissolved through various enzymatic processes.