Vitamin B2

Riboflavin or vitamin B2 is part of coenzymes flavinadenine mononucleotide (FAD) and flavin mononucleotide (FMN), plays a key role in oxidative metabolism.

Source
A small amount is found in many foods. Main sources are meat, milk and milk products; good sources are also fish, offal (inner organs), eggs, and whole grain cereals. Milling of cereals removes most of vitamin B2 - some countries (e.g. USA) fortify cereal products with riboflavin.

Recommended daily intake for adults: 1.2 to 1.5 mg

Deficiency
According to several population studies, the deficiency is widespread in developing countries, where diet is poor in animal foods, vegetables and fruits, and where cereals are milled (white flour). Frequently the deficiency is secondary due to malabsorption, enterocolitis, coeliac disease, chronic hepatitis; in children often after the use of broad-spectrum antibiotics. It may develop in cancer, cardiac disease, diabetes

Clinical picture: The description of the signs of riboflavin deficiency is somewhat inconsistent in various scientific publications. Riboflavin deficiency occurs almost always together with deficiencies of other group B vitamins, which may cause some of the signs decribed in literature. The signs most frequently described are: angular stomatitis, peeling lips (cheilosis), glossitis, and normocytic normochromic anemia.

Laboratory evaluation: decreases secretion of vitamin B2 in urine (normal values are 106–638 nmol/l ), decreased concentrations of glutathione and glutathione reductase in erythrocytes.

Excess
Signs of excess are not known.

Related articles

 * Fat Soluble Vitamins
 * Water Soluble Vitamins