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Abstract Summary 116 Summary Iron deficiency (ID) is the most common single-nutrient deficiency in the world. In many low- and middle-income countries, the prevalence of iron- deficiency anemia (IDA) among children under 5 years of age is at least 25%, and is often higher. The major causes of iron deficiency include inadequate dietary iron intake due to consumption of a diet with low overall iron content, or one that contains inhibitors of iron absorption, and increased losses of iron because of chronic blood losses, most commonly due to intestinal hookworm infection. Poor dietary intake and limited bioavailability (the quantity or fraction of the iron consumed that is absorbed and utilized) is considered a major contributor to the global burden of iron deficiency. Populations consuming diets that chiefly comprise cereals such as maize, wheat and rice, with an inadequate intake of iron-rich foods, in particular meat, but also legumes, nuts and other vegetables, are at high risk of iron deficiency. Cereals (including maize) contain phytates which bind to iron and prevent its absorption in the intestine . Also, iron deficiency is most likely to occur during times of increased iron requirements, and thus ID is seen most commonly in infants and young children when rapid growth results in expansion of the blood volume and an increase in iron requirements for production of red blood cells. Iron deficiency is associated with considerable morbidity across the life cycle. In preschool children, iron deficiency anemia appears to be associated with potentially irreversible impairments in cognitive Summary 117 development, and in school-aged children iron deficiency anemia is associated with reduced school learning and educational performance. In addition to direct effects on brain function, iron deficiency and iron deficiency anemia may also affect child development indirectly through non-responsive mother-child interactions. Maternal iron deficiency is a global problem that may contribute to high rates of maternal depression and non-responsive care-giving. Intervention trials illustrate that children benefit from both nutritional intervention and early learning interventions that promote responsive mother-child interactions. Iron deficiency anemia produces many systemic abnormalities: blue sclerae, koilonychia, impaired exercise capacity, irritability, atrophic glossitis, and an increased susceptibility to infection. Abnormal developmental performance and poor growth are particularly important features. The diagnosis of iron deficiency is based primarily on laboratory measurements. However, the tests used commonly have limitations due to their poor sensitivity or specificity, or because they are modified by conditions other than iron deficiency (such as inflammation). So, combining several iron status indicators provides the best assessment of iron status. Important laboratory indicators for evaluating the iron status include Evaluation of multiple indicators such as soluble transferrin receptors (sTfRs), sTfR–ferritin index (sTfR–F), zinc protoporphyrin / heme ratio (ZPP/H), reticulocyte hemoglobin (Hb) content (CHr) , ferritin, and transferrin/total iron binding capacity. Bone marrow examination for macrophage iron is considered a gold standard for diagnosis of iron deficiency, but it is rarely performed in field studies. Summary 118 Hepcidin (iron regulatory hormone secreted by liver) concentration reflects body iron, so, the ability to measure plasma or urinary hepcidin could potentially become the single most important test for monitoring iron status. However, progress in developing a simple, inexpensive and widely available hepcidin assay has been slow. Prevention of iron deficiency anemia during pregnancy has been associated in some studies with alleviation of low birth weight (which in turn is associated with reduced infant iron endowment and a subsequent increased risk of iron deficiency anemia. Maternal iron deficiency is global problem that may contribute to high rates of maternal depression and non-responsive care giving. Children can benefit from both nutritional interventions and early learning interventions that promote responsive mother-child interactions. Strategies to improve iron intake include improving over all dietary diversity, supplementation, point of use fortification of foods with micronutrient powders and fortification of staple foods with iron. Increasing the availability and consumption of a nutritionally adequate diet is the only sustainable and long-term solution, not just for overcoming iron deficiency and anemia, but for overcoming other micronutrient deficiencies as well. Food-based approaches include increasing overall food intake, increasing consumption of micronutrient-rich foods, modifying intake of dietary iron inhibitors and enhancers, using improved processing, preservation and preparation techniques, consumer education for behaviour change, improving food quality and safety and public health, and food fortification. |