Vitamin K deficiency is a very rare vitamin deficiency. Vitamin K is important in the body's use and uptake of certain types of proteins known as Gla-proteins that are responsible for the proper clotting of blood, the formation of bones, and maintaining blood vessels. The body extracts Vitamin K from food using the bacteria usually found in the intestines. If digestive processes are badly compromised, such as the death of the bacteria (from antibiotics, for example), the blockage of the bile duct, or massive intestinal damage, the body cannot use dietary Vitamin K and the symptoms appear: