Vitamin K refers to a group of vitamins which includes vitamin K1 and vitamin K2. Vitamin K1 is synthesized by plants. Vitamin K2 is mainly produced by both humans and animals, but also by bacteria found in the large intestine. The 'K' in vitamin K is derived from the German word "koagulation." Coagulation is the process in which blood forms clots. Vitamin K facilitates the function of several proteins, including those that are responsible for blood clot formation. It plays a vital role in cell growth and in the metabolism of bone and other tissues.
Vitamin K and Blood Clot Formation
Blood clots through a process called the 'coagulation cascade'. It's referred to as a cascade as it involves a cascade of enzymes activating each other. Fibrin is formed at the end of the cascade. Fibrin is the protein that clumps together to form part of the plug/clot in an attempt to stop bleeding. The activation of some of the enzymes in the coagulation cascade is also dependent on vitamin K. It is on this principle that oral anticoagulants like warfarin (Coumadin) function. While blood clots form naturally to stop us from hemorrhaging to death, they can also be dangerous if they lodge in the heart or blood vessels. This prevents blood from reaching its destination, resulting in the death of the target tissue. Anticoagulants are prescribed to patients at risk of forming such clots. These anticoagulants block vitamin K function, resulting in decreased formation of clots. It is primarily vitamin K1 that is used when it comes to blood clotting.
Vitamin K and Healthy Bones
Vitamin K2 plays an important role in bone formation. It is also involved in the prevention of bone loss. Vitamin K modifies the protein osteocalcin. This gives osteocalcin the ability to bind to calcium. Calcium can then help to form the bone matrix.
Recent research has shown that vitamin K also works with vitamin D to facilitate the function of osteoblasts, the bone building cells. On the other hand, it works to inhibit the production of osteoclasts (the cells which breakdown bone).
Vitamin K and Cell Growth
Gas6 is a protein that is important for regulating cell growth, proliferation and preventing cell death. Its function is dependent on vitamin K. It also helps cells to communicate with each other. Current research also suggests that this protein may be involved in the development and aging of the nervous system.
Vitamin K Prevents Cardiovascular Disease
When there is a deficiency of vitamin K, osteocalcin does not bind calcium. This means that calcium cannot bind to the bone matrix. With the lack of calcium bones eventually become porous. Calcium is then also free to travel in the blood, and eventually gets deposited in the arteries. This causes a hardening of the arteries, a condition also known as atherosclerosis.
Although vitamin K is widely known for its involvement in blood clotting, it has been shown to function within several systems in the body. It is also maintains healthy bones, facilitates cell growth and prevents cardiovascular disease.