Answer: riboflavin

AnswerCrossword Clue
RIBOFLAVINVitamin B-2.
riboflavina member of vitamin B complex, in yellowish-brown crystals, promoting growth in children also RIBOFLAVINE
riboflavinA yellow vitamin of the B complex that is essential for metabolic energy production. It is present in many foods, esp. milk, liver, eggs, and green vegetables, and is also synthesized by the intestinal flora