Vitamin B2 Powder (Bulk). Vitamin B2, also called Riboflavin, is a water-soluble vitamin. Vitamin B2 is needed to process amino acids and fats. Additionally, Riboflavin aids in the metabolism of carbohydrates, fats, and proteins. It plays an important role in the growth and healthy maintenance of joints, skin, hair, and nails. Carpal Tunnel Syndrome may benefit from a program that includes Riboflavin combined with Vitamin B6. The body needs Vitamin B2 for reproduction. Vitamin B2 also supports the natural functioning of the immune system. Under some conditions, Vitamin B2 may act as an antioxidant. This valuable vitamin also promotes healthy skin, nails and hair.