Riboflavin, also known as vitamin B2, is a water-soluble vitamin that plays a crucial role in energy production and the metabolism of fats, drugs, and steroids. It is essential for the maintenance of healthy skin, eyes, and nerve functions, and acts as an antioxidant. Riboflavin is found in various foods, including dairy products, eggs, green leafy vegetables, and fortified cereals. A deficiency can lead to symptoms such as sore throat, redness, and swelling of the lining of the mouth and throat, as well as cracks on the outsides of the lips and at the corners of the mouth.