Role of Iron in Body

Iron
What does it do? Iron is part of hemoglobin, the oxygen-carrying component of the blood. Iron-deficient people tire easily because their bodies are starved for oxygen. Iron is also part of myoglobin, which helps muscle cells store oxygen. Without enough iron, ATP (the fuel the body runs on) cannot be properly synthesized. As a result, some iron-deficient people become fatigued even when their hemoglobin levels are normal.
Although iron is part of the antioxidant enzyme catalase, iron is not generally considered an antioxidant, because too much iron can cause oxidative damage.
Where is it found? The most absorbable form of iron, called “heme” iron, is found in oysters, meat, poultry, and fish. Non-heme iron is also found in these foods, as well as in dried fruit, molasses, leafy green vegetables, wine, and most iron supplements. Acidic foods (such as tomato sauce) cooked in an iron pan can also be a source of dietary iron.
Who is likely to be deficient? Vegetarians eat less iron than nonvegetarians, and the iron they eat is somewhat less absorbable. As a result, vegetarians are more likely to have reduced iron stores. However, iron deficiency is not usually caused by a lack of iron in the diet alone; an underlying cause, such as iron loss in menstrual blood, often exists.
Pregnant women, marathon runners, people who take aspirin, and those who have parasitic infections, hemorrhoids, ulcers, ulcerative colitis, Crohn’s disease, gastrointestinal cancers, or other conditions that cause blood loss or malabsorption are likely to become deficient.
Individuals who fit into one of these groups, even pregnant women, shouldn’t automatically take iron supplements. Fatigue, the first symptom of iron deficiency, can be caused by many other things. A nutritionally oriented doctor should assess the need for iron supplements, since taking iron when it isn’t needed does no good and may do some harm.
How much is usually taken? If a nutritionally oriented doctor diagnoses iron deficiency, iron supplementation is essential. A common adult dose is 100 mg per day. When iron deficiency is diagnosed, the doctor must also determine the cause. Usually it’s not serious (such as normal menstrual blood loss or blood donation). Occasionally, however, iron deficiency signals ulcers or even colon cancer.
Many premenopausal women become marginally iron deficient unless they supplement with iron. Even so, the 18 mg of iron present in most multiple-vitamin/ mineral supplements is often adequate.
Are there any side effects or interactions? Huge overdoses (as when a child swallows an entire bottle of iron supplements) can be fatal. Keep iron-containing supplements out of a child’s reach. Hemochromatosis, hemosiderosis, polycythemia, and iron-loading anemias (such as thalassemia and sickle cell anemia) are conditions involving excessive storage of iron. Supplementing iron can be quite dangerous for people with these diseases.
Supplemental amounts required to overcome iron deficiency can cause constipation . Sometimes switching the form of iron, getting more exercise, or treating the constipation with fiber and fluids is helpful. Sometimes the amount of iron must be reduced if constipation occurs.
Some researchers have linked excess iron to diabetes cancer, increased risk of infection,4 systemic lupus erythematosus (SLE), exacerbation of rheumatoid arthritis, andheart disease, though a review of the best studies has found no link.10 None of these links has been proven. Nonetheless, too much iron causes free radical damage, which can cause or exacerbate most of these diseases. People who are not iron deficient should not supplement iron when potential risks might exist and no benefit can be found.
Caffeine, high-fiber foods, and calcium supplements reduce iron absorption. Vitamin C slightly increases iron absorption. Taking vitamin A with iron helps treat iron deficiency, since vitamin A helps the body use iron stored in the liver.
Deferoxamine is a drug that binds to some metals, including iron, and carries them out of the body. It is used to treat acute iron poisoning, chronic iron overload, and aluminum accumulation in people with kidney failure. People taking deferoxamine to treat iron overload must not take iron supplements, including the amounts found in many multivitamin/ minerals.
Penicillamine binds metals (including copper and iron) and carries them out of the body. When penicillamine and iron are taken together, penicillamine absorption and activity are reduced. Four cases of penicillamine- induced kidney damage were reported when concomitant iron therapy was stopped, which presumably led to increased penicillamine absorption and toxicity.