Vitamin B2
Vitamin B2 (riboflavin) is essential for the metabolism of carbohydrates (to produce energy) and amino acids. It also helps keep mucous membranes (such as those lining the mouth) healthy.
Vitamin B2 Deficiency
Vitamin B2 deficiency by itself is uncommon. It usually occurs with deficiencies of other B vitamins in people who have a protein and calorie deficiency. Chronic disorders, such as heart disease, cancer, and diabetes mellitus, and malabsorption disorders increase the risk of vitamin B2 deficiency, as can hemodialysis and peritoneal dialysis--procedures that filter the blood (see Section 11, Chapter 143).
Symptoms are vague. They include painful cracks in the corners of the mouth and on the lips and a sore mouth and tongue. The tongue may turn magenta, and greasy (seborrheic) patches may appear around the nose and in the area between the nose and the lips.
The diagnosis is based on the symptoms and evidence of general undernutrition (see Section 12, Chapter 153). Tests to confirm the diagnosis are not readily available. High doses of vitamin B2 are taken by mouth until symptoms resolve. Supplements of other B vitamins are also taken. People who are undergoing hemodialysis or peritoneal dialysis or who have a malabsorption disorder should take vitamin B2 supplements.
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