Facts About Iron

Part 3: Iron supplements and current issues and controversies about iron.

Iron deficiency and iron deficiency anemia are relatively common in women of childbearing age, older infants and toddlers, and teenage girls(38), so they should periodically be screened for iron deficiency. Within these groups, iron deficiency is more common among women with heavy menstrual losses, women belonging to minority and low-income groups, and women who have had more than one child(38). Women taking oral contraceptives may experience less bleeding during their periods and have a lower risk of developing an iron deficiency while women using an intrauterine device may experience more bleeding and have a greater risk of developing an iron deficiency. If laboratory tests indicate iron deficiency, iron supplements may be recommended. Many physicians routinely prescribe iron supplements during pregnancy because of the high incidence of iron deficiency anemia in pregnant women and the potential benefits for the mother and the fetus. Pregnancy increases a woman’s need for iron due to increased blood volume, increased needs of the fetus, and blood losses that occur during delivery(1,39).

Excluding all meat and meat products, poultry, and fish from your diet may reduce your total iron intake and will decrease your intake of heme iron, which is easily absorbed by your body. It will also influence your iron status because animal proteins can improve the absorption of nonheme iron found in plant foods. Vegetarians who exclude all animal products from their diet may need twice as much dietary iron because the intestinal absorption of nonheme iron is lower in plant foods(1). Vegetarians should also consider consuming nonheme iron sources together with a good source of vitamin C, such as citrus fruits or certain vegetables, to enhance absorption of nonheme iron.

Iron supplementation is indicated when an iron deficiency is diagnosed and diet alone cannot restore bodily iron content to normal levels within an acceptable time frame. Iron in supplements comes in two forms: ferrous and ferric. The ferrous form is better absorbed and is usually the preferred form when iron deficiency has been diagnosed(40-42).

Supplemental iron may cause gastrointestinal side effects such as nausea, vomiting, constipation, diarrhea, dark colored stools, and/or abdominal distress(43). To minimize these side effects, start with half the recommended dose, gradually increasing to the full dose. Taking the supplement in divided doses and with food also may help limit these symptoms (44).

Iron deficiency is uncommon among adult men and postmenopausal women. These individuals should only take iron supplements when prescribed by their qualified health care provider because of the risk of iron overload. Iron overload is a condition in which excess iron is found in the blood and stored in organs such as the liver and heart. Iron overload is associated with several genetic diseases including hemochromatosis, which affects approximately 1 in 250 individuals of northern European descent(45). Individuals with hemochromatosis absorb iron very efficiently, which can result in a build up of excess iron in organs and can cause organ damage such as cirrhosis of the liver and heart failure(1,3,46-48). This condition often is not diagnosed until the excess iron stores have damaged an organ. Iron supplementation may accelerate the effects of hemochromatosis, an important reason why adult men and postmenopausal women who are not iron deficient should not take iron supplements. Individuals with blood disorders who require frequent blood transfusions are also at risk of iron overload and should not take iron supplements.

Issues and controversies about iron

• 1
• 2
• 3
• 4