Iron-Deficiency Anemia Usually Preventable with Good Nutrition

Although there are several types of anemia, by far the most common is caused by a shortage of iron in the blood. Iron is essential for the body to make hemoglobin, the protein that carries oxygen from the lungs to the rest of the body.

In iron-deficiency anemia, the blood has too few red blood cells or the red blood cells don't have enough hemoglobin; as a result, tissues and organs don't receive the amount of oxygen they need to function optimally. Iron-deficiency anemia can cause an array of symptoms that are most often mild, but can be severe if the deficiency becomes critical.

"Not only is iron important for your red blood cells, but it is an essential element for the energy machine of every cell in your body, including the ones in your brain," says John Paul Scott, MD, Medical College of Wisconsin Professor of Pediatrics, who practices at the Children's Hospital of Wisconsin Hematology/Oncology Clinic.

Anemia in Adults
In adults, anemia most often causes weakness and fatigue. When iron is very low, adults might also experience low body temperature, pale skin, rapid heartbeat, shortness of breath, lethargy, headaches and chest pain.

Iron-deficiency anemia can result from a diet that is too low in iron, inadequate iron absorption, or excessive blood loss.

Women of childbearing age, pregnant women, and adolescent girls are at high risk of developing iron-deficiency anemia. (Women taking oral contraceptives may experience less bleeding during their periods and have a lower risk of developing an iron deficiency.) Girls and women with heavy menstrual bleeding can lose a significant amount of iron and often require supplemental iron; Dr. Scott notes that there are a wide variety of vitamins available that are made specifically to meet the needs of this group.

Gastrointestinal disorders such as celiac disease and Crohn's syndrome result in inflammation of the small intestine and can cause diarrhea, poor absorption of dietary iron, and hidden bleeding, all of which contribute to iron depletion.

Vegetarians who exclude all animal products from their diet might need almost twice as much dietary iron each day as non-vegetarians because of the lower intestinal absorption of iron in plant foods.

Unless there is excessive bleeding, iron-deficiency anemia can be avoided through getting enough iron in the diet or, if necessary, from supplements.

Anemia in Infants and Children
Anemia usually develops slowly in children, and children with anemia often have few or no outward signs of illness, although they might appear somewhat pale.

In pediatrics, the classic cause of iron deficiency is a diet of cow's milk. The amount of iron in cow's milk is low, and infants poorly absorb it, while iron in human breast milk is well absorbed by infants.

"Cow's milk, to use one of the oldest expressions in pediatric medicine, is for baby cows. It's not designed for humans," Dr. Scott notes. "Breast milk comes 'prepackaged' and is readily available, and manufactured on a daily basis if the mom has enough to eat and drink," he says.

"I have been in pediatrics for 33 years and breast feeding has always been the recommendation, but for some moms and babies it is not possible. In those circumstances, iron-supplemented formula is the treatment of choice for protection against iron-deficiency anemia."

The American Academy of Pediatrics (AAP) recommends that infants be exclusively breast fed for the first six months of life; cow's milk should not be fed to infants until they are at least 1 year old.

Since iron is needed for normal brain function, there is concern that children who are chronically iron-deficient might experience learning and behavioral problems; but in almost all cases, these problems are resolved by adding iron-containing foods or an iron supplement to the child's daily diet.

Preventing Iron-Deficiency Anemia
With a little effort, it's usually possible to get enough iron from dietary sources.

Red meat such as beef and liver are especially high in iron, but chicken, turkey, pork, fish, and shellfish are also good sources. Iron found in meats is more easily absorbed into the blood than the iron found in vegetables and other foods.

Vegetarians should try to eat plant foods that are higher in iron - such as beans, tofu, and spinach, together with good sources of vitamin C, which improves iron absorption.

Vegetables and fruits are good dietary sources of vitamin C, especially citrus fruits such as oranges, grapefruit, and tangerines. Vegetables rich in vitamin C include broccoli, peppers, tomatoes, cabbage, potatoes, and leafy green vegetables like romaine lettuce, turnip greens, and spinach.

Fresh and frozen fruits, vegetables, and juices usually have more vitamin C than canned ones.

Many cereals, breads, and pasta products are fortified with extra iron. The amount of iron will be noted on the nutrition labels on the package.

Adult men and post-menopausal women lose very little iron, and have a low risk of iron deficiency, so they should only take iron supplements when prescribed by a physician. Having too much iron can lead to overload and the possibility of iron toxicity.

This article includes information from the National Heart Lung and Blood Institute and the National Institutes of Health Office of Dietary Supplements (ODS). The ODS website contains listings of the amount of iron per serving of selected foods and the Recommended Dietary Allowances (RDAs) for iron for infants, children, and adults.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.