Riboflavin is necessary for red blood cell formation, antibody production, cell respiration and growth. It alleviates eye fatigue and is important in the prevention and treatment of cataracts. It aids in the metabolism of carbohydrates, fats, and proteins. Together with vitamin A it maintains and improves the mucous membranes in the digestive tract. Riboflavin also facilitates  the use of oxygen by the tissues of the skin, nails, and hair; eliminates dandruff; and helps absorption of iron and vitamin B-6 (pyridoxine). 

Consumption of adequate amounts of riboflavin is important  during pregnancy, because a lack of this vitamin can damage a developing fetus even if a woman shows no signs of deficiency. Riboflavin is needed for the metabolism of the amino acid tryptophan, which is converted into niacin in the body. Carpel tunnel syndrome may benefit from a treatment program that includes riboflavin and vitamin B-6. 

Deficiency symptoms  includes cracks and sores at the corners of the mouth, eye disorders, inflammation of the  mouth and tongue, skin lesions, a group of symptoms collectively referred to as "ariboflavinosis". Other possible deficiency symptoms include dermatitis, dizziness, hair loss, insomnia, light sensitivity, poor digestion, retarded growth, and slowed mental response.