The forms of iron currently available have serious adverse effects that limit their use in addressing prevalent iron deficiency. Iron-supplementation programs have been frustrated by the serious side effects of inorganic forms of iron, which, due to low enteric absorptive efficiency, must be given in relatively high levels (5-20 fold effective levels of heme-iron in foods). Those adverse effects include infectious diarrhea, changes in the gut microbiome and increased serious morbidity among iron-replete children in malaria-endemic areas. The underlying causes of these effects are thought to involve stress on the gut due to excess unabsorbed iron, which can be pro-oxidative and pro-inflammatory. In addition, unabsorbed, soluble iron can be used by the gut microbiome and favor the proliferation of pathogenic enteric bacteria which can contribute to the inflammatory response that leads to down-regulation of iron absorption. Lack of a safe and effective treatment leaves large numbers of children iron deficient, many with associated anemia. Thus, the burden of disease, which includes growth, cognitive and physical performance deficits as well as increased risk of infection, continues to climb in this age group.