Iron Deficiency Anemia

In iron deficiency anemia, an inadequate supply of iron for optimal formation of red blood cells (RBCs) results in smaller (microcytic) cells with less color on staining. Body stores of iron, including plasma iron, decrease, as does transferrin, which binds with and transports iron. Insufficient body stores of iron lead to a depleted RBC mass and, in turn, a decreased hemoglobin (Hb) concentration (hypochromia) and decreased oxygen-carrying capacity of the blood. A common disease worldwide, iron deficiency anemia affects 10% to 30% of the adult population of the United States.

Iron deficiency anemia is the most common form of anemia. About 20% of women, 50% of pregnant women, and 3% of men are iron deficient.

Some people with iron deficiency anemia always feel cold. They feel cold because iron plays a role in regulating the body's temperature.

You can usually correct iron deficiency anemia with iron supplementation. Sometimes, other treatments are necessary if you're bleeding internally.

Causes

Iron deficiency anemia may result from:

• inadequate dietary intake of iron (< 2 mg/day), as in prolonged, unsupplemented (not eating solid foods after age 6 months) breast- or bottle-feeding of infants and during periods of stress, such as rapid growth in children and adolescents
• iron malabsorption, as in chronic diarrhea, partial or total gastrectomy, and malabsorption syndromes such as celiac disease
• blood loss secondary to drug-induced GI bleeding (from anticoagulants, aspirin, steroids) or due to heavy menses, hemorrhage from trauma, GI ulcers, cancer, or bleeding varices
• pregnancy, which diverts maternal iron to the fetus for erythropoiesis
• intravascular hemolysis-induced hemoglobinuria or paroxysmal nocturnal hemoglobinuria
• mechanical erythrocyte trauma caused by a prosthetic heart valve or vena cava filters.

Iron deficiency anemia occurs most commonly in premenopausal women, infants (particularly premature and low­birth-weight infants), children, and adolescents (especially girls).

Signs and symptoms

The following are the most common symptoms of iron deficiency anemia. However, each child may experience symptoms differently. Symptoms may include:

• abnormal paleness or lack of color of the skin
• irritability
• lack of energy or tiring easily (fatigue)
• increased heart rate (tachycardia)
• sore or swollen tongue
• enlarged spleen
• dizziness or a feeling of being lightheaded

Rarely, a person with iron-deficiency anemia may experience pica , a craving to eat nonfood items such as paint chips, chalk, or dirt. Pica may be caused by a lack of iron in the diet.

Diagnosis

To diagnose iron-deficiency anemia, the doctor may look at the patient's medical history and symptoms to determine what tests should be done. A blood test in combination with a test for oral iron absorption may confirm the diagnosis. The doctor may also want to check the patient's stools or get x-rays of the bowel to determine if blood loss is a cause of the anemia.

Treatment

The first priority of treatment is to determine the underlying cause of anemia. When this is determined, iron replacement therapy can begin. The treatment of choice is an oral preparation of iron or a combination of iron and ascorbic acid (which enhances iron absorption). In some cases, iron may have to be administered parenterally, for instance, if the patient is noncompliant to the oral preparation, if he needs more iron than he can take orally, if malabsorption prevents adequate iron absorption, or if a maximum rate of Hb regeneration is desired.

Because a total-dose I.V. infusion of supplemental iron is painless and requires fewer injections, it's usually preferred over I.M. administration, Pregnant patients and elderly patients with severe anemia, for example, should receive a total-dose infusion of iron dextran in normal saline solution over 8 hours. To minimize the risk of an allergic reaction to iron, an LV. test dose of 0.5 ml should be given first.

Foods high in iron

• Liver and other meats
• Seafood
• Dried fruits like apricots, prunes and raisins
• Nuts
• Beans, especially lima beans
• Green leafy vegetables, such as spinach and broccoli
• Blackstrap molasses
• Whole grains
• Iron-fortified breads and cereals (check the label)

Prevention

Everyone's diet should include adequate amounts of iron. Red meat, liver, and egg yolks are important sources of iron. Flour, bread, and some cereals are fortified with iron. If you aren't getting enough iron in your diet (uncommon in the U.S.), iron supplements should be taken.

During periods of increased requirements, such as pregnancy and lactation, increase dietary intake or take iron supplements.