The discovery of biotin or vitamin B7 occurred in response to research investigating the cause of what was then called ‘egg white injury’.
In 1924 three factors were identified s necessary for the growth of microorganisms. They were called bios II, vitamin H, and coenzyme R. It soon became clear that all three were the same water soluble, sulfur containing vitamin – biotin.
Biotin is a bicyclic compound; one of the rings contains an ureido group and the other contains sulfur in a tetrahydrothiophene ring with a valeric acid side chain.
In food, mostly meats and protein, biotin is found both free and bound to protein. The protein bound form can liberated via proteases yielding free biotin forms, predominantly biotin and secondary biocytin.
Although biotin is widely distributed in foodstuff, the concentration is low compared to the other water-soluble vitamins.
Biotin in foods is fairly widespread because it is found in every living cell. Biotin is found in highest concentration in the liver. In food, biotin is present in relatively high concentrations in cereals, including soybeans, rice, barley, oats, corn and wheat. It is also high content in certain ocean fish.
Although egg yolk area concentrated source of biotin, whites contain a protein called avidin that has an extremely high affinity for biotin and substantially decreases its availability for absorption.
Biotin deficiency leads to impairment of gluconeogenesis and fat metabolism. Biotin deficiencies can also induce severe metabolic acidosis.
The vitamin of biotin