B2, also known as riboflavin, 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 growth and development of cells and helps maintain healthy skin, eyes, and nerve functions. Riboflavin is found in various foods, including dairy products, eggs, green leafy vegetables, nuts, and enriched cereals. A deficiency in B2 can lead to symptoms such as sore throat, redness and swelling of the lining of the mouth and throat, and cracks or sores on the outsides of the lips and at the corners of the mouth.