Biotin supplements are used to prevent or treat biotin deficiency.Vitamins are compounds that you must have for growth and health. They are needed in only small amounts and are usually available in the foods that you eat. Biotin is necessary for formation of fatty acids and glucose, which are used as fuels by the body. It is also important for the metabolism of amino acids and carbohydrates.A lack of biotin is rare. However, if it occurs it may lead to skin rash, loss of hair, high blood levels of cholesterol, and heart problems.