Iron intake and regulation: implications for iron deficiency and iron overload.

Although iron deficiency anemia is the most common nutritional deficiency worldwide and in the United States, the health effects of iron overload merit increased attention. In the United States, public health interventions such as fortification and enrichment of foods with iron were undertaken to reduce the prevalence of iron deficiency anemia and improve health. These measures, along with iron supplementation, remain controversial, because additional exposure to dietary iron places some segments of the population at increased risk of iron excess. The health consequences of unmistakable iron excess are exemplified by hemochromatosis, an iron storage disease associated with liver damage further exacerbated by alcohol consumption. Progressive liver damage associated with this condition is generally attributed to increased oxidative stress. In otherwise healthy individuals, more modest levels of iron storage may occur if iron is provided by supplements or otherwise added to the food supply. Increased iron intake and storage have been linked to a variety of chronic diseases. The associations are not firmly established but are of considerable public health importance.