Vitamin B-2, also known as riboflavin, is a member of the B-vitamin family. It occurs naturally in green vegetables, liver, kidneys, wheat germ, milk, eggs, cheese and fish. Riboflavin is an important enzyme cofactor necessary for energy production from carbohydrate, fat, and protein. It is also needed for the regeneration of glutathione, which supports the body natural defense mechanisms and detoxification systems.