Iron: deficiencies and requirements

A report from the World Health Organization estimates that 46% of the world 's 5- to 14-year-old children are anemic. In addition, 48% of the world's p regnant women are anemic. A majority of these cases of anemia are due to ir on deficiency. Our aim here is to review the latest data on iron regulatory mechanisms, iron sources and requirements. Human and animal studies have s hown that amino acids and peptides influence iron absorption from the intes tinal lumen. Inter-organ transport and uptake of nonheme iron is largely pe rformed by the complex transferring-transferring receptor system. Moreover, the discovery of cytoplasmic iron regulatory proteins (IRPs) has provided a molecular framework from which we understand the coordination of cellular iron homeostasis in mammals. IRPs and the iron responsive elements (IREs) to which they bind allow mammals to make use of the essential properties of iron while reducing its potentially toxic effect. Physiologic iron require ments are three times higher in pregnancy than they are in menstruating wom en (approximately 1200 mg must be acquired from the body's iron store or fr om the diet by the end of pregnancy). The administration of iron supplement s weekly instead of daily in humans has been proposed and is being actively investigated as a viable means of controlling iron deficiency in populatio ns. including pregnant women. (C) 2001 Editions scientifiques et medicales Elsevier SAS.