Iron has many biological functions, but its main job is to aid in the transport of oxygen and carbon dioxide to and from body cells. Iron also is essential for the normal functioning of the immune system. The best plant sources are dark green, leafy vegetables, legumes, nuts, seeds, dried fruits, and enriched or whole-grain breads and cereals. The use of iron cooking pots and skillets can increase the iron in food. Acidic foods with a high moisture content that are simmered for a long time, such as chili or spaghetti sauce, gain more iron than foods prepared quickly, such as a fried egg.
Iron deficiency is the most common nutritional deficiency.
It is also the most common cause of anemia among children and women during childbearing years in the United States and worldwide. Iron deficiency can be caused by a poorly balanced diet, injury, hemorrhage, or illness. Groups considered most at risk are infants, teenage girls, pregnant women, and the elderly. Pregnant teenagers are frequently at very high risk. The final stage of iron deficiency is anemia.