Iron toxicity results from an iron overload and is most prevalent among small children who accidentally ingest iron supplements. When iron atoms circulating in the blood exceed the availability of molecules in the body that bind with iron, damage to organs begins. The first signs of iron poisoning are stomach pain and vomiting, as the lining of the stomach and intestines is harmed. Left untreated, organ damage continues with potential lethal consequences due to organ failure.
The body regulates iron intake from food, so iron toxicity usually results from supplements rather than dietary sources of iron. Supplements containing iron are used to treat anemia and as a part of prenatal care. One of the most tempting forms is children’s vitamin tablets with added iron. Poisoning symptoms begin when iron intake is as low as 0.00035 ounces per 2.2 pounds (10 milligrams per kilogram) of body weight, although the toxic dose varies by individual.
Iron toxicity is a leading cause of poisoning deaths in young children. People who require frequent blood transfusions are also susceptible to iron poisoning. Rare cases of intentional iron overdose in adults have occurred. Certain genetic diseases can cause chronic iron overload.
The corrosive nature or iron first damages the lining of the gastrointestinal tract with symptoms appearing within six hours of overdose. The iron then migrates to other organs where cell damage occurs. Particularly susceptible organs are the liver, brain, heart and kidneys. Iron toxicity causes cellular death within organs, which leads to organ failure.
Several treatment options are available and depend on the severity of the iron overload. If caught quickly enough, pumping the stomach might be effective. A strong laxative can be given to cleanse the intestines. Severe overload is treated using chelation therapy that binds the iron to a chemical which is then excreted.
Required by most forms of life, iron is a highly reactive atom capable of both accepting and donating electrons. This reactivity makes the essential element toxic when iron levels in the body are too high. Iron metabolism binds atomic iron to proteins to prevent it from chemically reacting with hydrogen peroxide to form cell-damaging free radicals. Bound iron is essential to many metabolic processes within the body.
Over half of the iron in the human body is found in hemoglobin, the oxygen-carrying molecule in red blood cells. Lack of sufficient iron can result in iron deficiency anemia. Iron is stored in the body to prevent deficiencies. It is found in the liver, bone marrow and the spleen where it is bound to ferritin molecules. Iron is also recycled in the body as old red blood cells are broken down.