The B-vitamins are required for energy production and the synthesis and metabolism of various biological substances.
Major B-2 deficiencies can be caused by low consumption of milk, chronic alcoholism, or chronic diarrhea, and result in lesions
of the skin and digestive tract, and nervous disorders. Minor deficiencies — sometimes caused by pregnancy, lactation, birth
control pills, and regular strenuous exercise — can have, as symptoms, numbness and decreased sensitivity, oily scaly skin
rashes, inflammation of the tongue and lips; and red, itchy, oversensitive eyes.