Foods rich in iron include beef and chicken liver; seafood such as clams, mollusks, mussels, oysters and sardines; and plant sources such as spinach, beans, tofu, pumpkin seeds and sesame seeds. Other good sources of iron are sardines, turkey, lima beans, dried apricots and baked potatoes. Animal foods supply a form of iron called heme iron, which the body absorbs easily, in contrast to non-heme iron, which comes from plant foods and is harder for the body to absorb.
Iron is an important component of hemoglobin, the protein in red blood cells that allows them to transport oxygen to the body's cells. Without oxygen, the body's cells cannot produce energy, and insufficient iron in the blood results in a condition known as iron-deficiency anemia, which causes weakness, fatigue and irritability.
Despite iron's wide availability in many food groups, iron deficiency remains the most common nutritional deficiency worldwide. Children, women of reproductive age and people who eat poorly are most susceptible. Without treatment, anemia leads to irregular heartbeat, pregnancy complications and stunted growth in children.
Iron also forms part of the cytochrome electron transport system within cells and is a component of myoglobin, which supplies oxygen to muscle cells. Iron is also necessary for the normal function of many enzymes. A lack of iron disrupts these vital enzymatic reactions, which can lead to illness and death.