What Are the Vitamin K Dependent Factors?

Vitamin K is essential in creating a range of proteins involved in the process of coagulation and anticoagulation of blood. People who are deficient in vitamin K tend to bleed excessively. There are two forms of vitamin K that occur naturally and they are named respectively vitamins K1 and K2. Several of the proteins involved in coagulation are dependent on Vitamin K. These proteins are known as factors. Deficiency in the vitamin K-dependent factors can lead to bleeding disorders.

Coagulation Cascade

The coagulation cascade refers to a set of activities the body initiates whenever you bleed. The end result and object of the coagulation cascade is to make the blood clot. Coagulation factors are special proteins involved in the coagulation process and the reaction of each factor activates the next reaction in the process.

Key Vitamin K Dependent Factors

The main vitamin K-dependent coagulation proteins are factor II, also known as prothrombin -- and factors VII, IX and X. Deficiency in any of these factors can disrupt the clotting process and result in a range of bleeding problems.

Factor II

Deficiency in the vitamin K-dependent factor II, prothrombin can be the result of a deficiency that may be present at birth or one that is acquired later. Congenital factor II deficiency is passed down in families with the disorder and is extremely rare as it requires both parents to be carriers of the gene that codes for the disorder. People with the disorder have poor blood clotting and bleed easily. On the other hand, acquired factor II deficiency is much more prevalent. Liver disease, a lack of vitamin K, as well as the use of certain drugs may cause the factor II deficiency. Some of the symptoms of factor II deficiency are nose bleeds, post-trauma bleeding and post-surgery bleeding.

Factor VII

A lack of the vitamin K-dependent factor VII is an inherited disorder that results in abnormal coagulation. The disorder is also known as extrinsic factor deficiency. Symptoms of this disorder include nose bleeds, bruising and bleeding into joints and muscles. The bleeding, which can also occur in the gastrointestinal system, can be severe and starts most commonly during childhood. Treatment of people with this disorder during bleeding episodes involves using infusions of plasma from a healthy donor, or concentrates of factor VII.

Factor IX

People who suffer from hemophilia B are deficient in the factor IX coagulation protein which is a vitamin K-dependent factor. Factor IX deficiency is also known as Christmas disease and was first diagnosed in 1952. In this mostly inherited disorder, the patient is either missing, or has a reduced amount, of the factor IX protein that helps with the formation of blood clots.

Factor X

About one in every 500,000 people suffer from a deficiency of the vitamin K-dependent factor X. The disorder is inherited and the bleeding that results can be severe. Amyloidosis is another disorder that results in a deficiency of factor X and can be treated by surgical removal of the spleen.