Prothrombin is a protein and clotting factor which is required for bone metabolism and the blood to clot. The body cannot produce prothrombin without vitamin K. This vitamin is responsible for blood clotting as it helps in regulating the blood coagulation process by assisting in the conversion of some coagulation factors to their mature forms.
Now for a further detailed understanding of the role of the vitamin in blood clotting, one must have an idea about the regulation of the formation of a blood clot. For that, it is important to be clear about hemostasis. The term hemo refers to blood, and stasis means to stop or halt. Hemostasis can be divided into two phases, namely, secondary and primary hemostasis.
Primary hemostasis includes the generation of a platelet plug surrounding the site of the damaged blood vessel. On the other hand, secondary hemostasis creates a protein mesh known as fibrin and reinforces the platelet plug.
A set of coagulation factors should be activated in order to get to fibrin. All of these coagulation factors are enzymes that are activated through a process known as proteolysis. There are a total of 12 coagulation factors, starting from I to XIII – a factor VI is not present. It is these factors’ assimilation where vitamin K is essential for the blood clotting process.
A majority of these factors are formed by the liver cells, and the production of the coagulation factor II, VII, IX and X need an enzyme that utilises vitamin K. All of this answers your query as to which vitamin is essential for blood clotting.