Vitamin B2, also called riboflavin, is important for energy production, enzyme function, and normal fatty acid and amino acid synthesis. It is also necessary for the reproduction of the antioxidant glutathione. Vitamin B2 is water-soluble like the reset of the B vitamins. It is not stored in ample amounts and excess is typically lost through urination, causing bright yellow urine, meaning a constant supply of vitamin B2 is needed. Deficiency in this vitamin is usually part of a multiple-nutrient deficiency and does not occur in isolation.Deficient B2 levels can lead to: Sore/red tongueCheilosis (chapping/fissuring of lips)Oily, scaly skin rashes on scrotum, vulva or philtrum of lipsVitamin B2 deficiency is also associated with the following birth defects or developmental abnormalities: Cleft lip and palateRetardation of growth in infants and childrenCongenital heart defectsMajor sources of vitamin B2 include: Fortified cereals and grainsMilk, yogurt, cheesesDark green vegetables (broccoli, spinach, asparagus)MeatVitamin B2 deficiency can be more prevalent in people who: Have kidney or heart failureAre alcoholicsHave cirrhosisHave hyperthyroidismAre taking anticonvulsants or corticosteroidsAre living with digestive disorders