Biotin is a water-soluble vitamin also known as vitamin B7 or vitamin H. It is an essential nutrient that plays a vital role in maintaining healthy skin, hair, and nails. Biotin is also important for the metabolism of carbohydrates, fats, and proteins, and is involved in the production of energy in the body. It is commonly used as a dietary supplement to promote healthy hair, skin, and nails, and to support overall health and wellness.