Natural Factors Biotin - 5000 mcg - Promotes strong, healthy nails, hair, and skin, combats biotin deficiency, and supports the breakdown of food into energy. Biotin encourages the growth of strong, thick, healthy-looking hair and can help reverse the loss of hair and hair colour that may result from a biotin deficiency. Biotin is a B-complex vitamin (B7), and is vital for the energy metabolism of carbohydrates, fats, and proteins. It is sometimes recommended alongside standard treatments for diabetes.