Vitamin K

Vitamin-k-zyklus

Vitamin K is a group of structurally similar, fat-soluble vitamins found in foods and marketed as dietary supplements. The human body requires vitamin K for complete synthesis of certain proteins that are prerequisites for blood coagulation (clotting) and which the body also uses for controlling binding of calcium in bones and other tissues.

Biological Role

Vitamin K is essential for the functioning of several proteins involved in physiological processes. Necessarily, it is a key vitamin in the regulation of blood clotting (coagulation). Without vitamin K, blood would not clot, and severe bleeding could occur.

In addition, Vitamin K plays a vital role in maintaining bone health. It aids in the regulation of calcium and is involved in the process of bone mineralization.

Sources

Vitamin K is found in various foods including green leafy vegetables, such as spinach and kale, and in some fruits, such as blueberries and figs. It is also produced by the bacteria in the intestines.

Deficiency and Overdose

A deficiency in vitamin K can lead to defective blood clotting, increased bleeding and osteoporosis. Symptoms of a vitamin K deficiency can include easy bruising, excessive bleeding from wounds, heavy menstrual periods, and blood in the urine or stool.

Vitamin K toxicity is rare but could potentially cause the breakdown of red blood cells and liver damage. Signs of an overdose include a flushed face, irritability, difficulty feeding, and a bulging fontanel (soft spot) in infants.

See Also

• Vitamin
• Blood clotting
• Calcium
• Bleeding diathesis