Iron

What does iron 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 iron 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 iron 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 iron is usually taken?

If a nutritionally oriented doctor diagnoses iron deficiency, iron supplements are 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.