Biotin has a reputation for helping improve the health of hair, skin and fingernails because it improves the structure of keratin. Keratin is the main protein hair, skin and nails are made of (also feathers, horns, hooves and claws in animals). Biotin is involved in the protein synthesis that forms keratin, which explains why it is associated with strong and healthy hair, skin and nails.
Biotin is also needed both for production and function of enzymes that metabolize carbs, fats and protein. Biotin both supports metabolic function and can elevate your resting metabolic rate (causing food to break down faster) when consumed.
Biotin deficiency is associated with pregnancy, long-term tube feeding, malnutrition, and rapid weight loss. Biotin is also used orally for hair loss, brittle nails, skin rash diabetes, mild depression and in high doses to treat Multiple Sclerosis.