A vitamin in the vitamin B complex. It is the coenzyme for various enzymes that catalyse the synthesis of fat, glycogen, and amino acids. Adequate amounts are normally produced by the intestinal bacteria in animals although deficiency can be induced by consuming large amounts of raw egg white. This contains a protein, avidin, that specifically binds biotin, preventing its absorption from the gut. Other sources of biotin include cereals, vegetables, milk, and liver. Symptoms of deficiency include skin inflammation and neuromuscular disorders.