Vitamin B2 (Riboflavin) is a nutrient that is essential for energy production and the metabolism of carbohydrates, fats, and proteins. Riboflavin is found in small quantities (less than 1 mg) in a variety of foods, but some individuals may benefit from much higher doses. B2-400 is a unique formula that provides 400 mg of pure riboflavin per capsule.  Research suggests that 400 mg of riboflavin per day may help certain individuals maintain mental clarity, healthy mood, and optimal productivity.