What is Biotin? It is a vitamin, commonly found in what we eat such as eggs, milk, and biotin, although they don't supply a large amount of this vitamin. Biotin is an important component of enzymes that break down certain substances like fats, carbohydrates, etc. Because of that, it is thought that biotin can help with hair loss, brittle nails, facial rashes, and even depression, fatigue and tingling in your arms/ legs. Simply Nutrients offers biotin supplements to help support your health.