The New York Times Health Guide explains that the human body needs iron to make the oxygen-carrying proteins hemoglobin and myoglobin. The University of California at San Francisco's Medical Center states that hemoglobin transfers oxygen in the blood from the lungs to the tissues. Myoglobin in the muscle cells accepts, stores, transports and releases oxygen.
The NYT Health Guide also explains that iron makes up part of many proteins in the body. However, the UCSF Medical Center states that the body does not naturally produce iron, so the body must absorb iron from foods. Iron-rich foods include dried beans, dried fruit, eggs, iron-fortified cereal, lean red meat, liver, oyster, poultry or dark red meat, salmon, tuna and whole grains.
When the body does not get enough iron, it may succumb to iron deficiency anemia. Symptoms of an iron deficiency include lack of energy, shortness of breath, headache, irritability, dizziness and weight loss. People with a rare genetic disorder called hemochromatosis take in too much iron. In addition, children who take too many iron supplements may develop iron poisoning. Symptoms of iron poisoning include anorexia, dizziness, fatigue, graying color to the skin, headache, nausea, shortness of breath, vomiting and weight loss.