Iron Deficiency Anemia
What is iron deficiency anemia?
The most common cause of anemia or low red blood cells is iron deficiency. Iron is essential to the formation of hemoglobin, which is the oxygen carrying molecule in red blood cells. When iron stores are low, hemoglobin can not be formed, leading to fewer red blood cells. A smaller portion of iron is stored as ferritin and hemosiderin in the bone marrow, spleen and liver.
Causes of iron deficiency anemia
Iron deficiency anemia can be caused by:
- Diets low in iron — Iron is obtained from foods in our diet, however, only 1 mg of iron is absorbed for every 10 to 20 mg of iron ingested. Premature infants have low iron stores and generally require iron supplementation early on. An exclusively breastfed infant will require additional iron sources by four to six months of age as the bioavailability of iron in the breastmilk is low. Cow milk consumption greater than 24oz or 3 cups daily in children, who are picky eaters as well, may lead to iron deficiency due to blood loss and a low iron diet.
- Body changes — An increased iron requirement and increased red blood cell production is required when the body is going through changes such as growth spurts in children and adolescents.
- Blood loss — Loss of blood can cause a decrease of iron and result in iron deficiency anemia. Early introduction to cow's milk, which is low in iron, can lead to occult blood loss in the stool and therefore is generally not recommended for children less than one year of age. Other sources of blood loss include gastrointestinal diseases such as inflammatory bowel disease, menstrual bleeding and injury.
- Gastrointestinal tract abnormalities — Malabsorption of iron is common after some forms of gastrointestinal surgeries. Most of the iron taken in by dietary route is absorbed in the upper small intestine. Any abnormalities in the gastrointestinal tract could alter iron absorption and result in iron deficiency anemia.
Signs and symptoms of iron deficiency anemia
Each child may experience different symptoms or varying severity of symptoms from iron deficiency anemia. Symptoms may include:
- Abnormal paleness or lack of color of the skin
- Lack of energy or tiring easily (fatigue)
- Increased heart rate (tachycardia)
- Sore or swollen tongue
- Enlarged spleen
- A desire to eat peculiar substances such as dirt or ice (also called pica)
Testing and diagnosis for iron deficiency anemia
Diagnosing iron deficiency anemia begins with a complete medical history, a physical examination and blood test.
- Blood tests are ordered to measure the amount of hemoglobin in the blood. Other tests may include reticulocyte count, which is a measure of young red blood cells, as well as iron studies to evaluate the body's iron stores.
- Bone marrow aspiration and/or biopsy is rarely necessary and is completed with the consultation of a hematologist.
Treatments for iron deficiency anemia
Specific treatment for iron deficiency anemia is determined by multiple factors including rectifying the cause of the anemia, such as blood loss, and iron supplementation.
Iron supplements can be taken over several months to increase iron levels in the blood. Iron supplements can cause irritation of the stomach and discoloration of bowel movements. They should be taken on an empty stomach or with orange juice to increase absorption. Always consult your child's physician regarding the recommended daily iron requirements for your child.
An iron-rich diet
Eating a diet with iron-rich foods can help treat iron deficiency anemia. Good sources of iron include the following:
- Meats — beef, pork, lamb, liver, and other organ meats
- Poultry — chicken, duck, turkey, liver (especially dark meat)
- Fish — shellfish, including clams, mussels, and oysters, sardines, anchovies
- Leafy greens of the cabbage family — broccoli, kale, turnip greens, and collards
- Legumes, such as lima beans and green peas; dry beans and peas, such as pinto beans, black-eyed peas, and canned baked beans
- Yeast-leavened whole-wheat bread and rolls
- Iron-enriched white bread, pasta, rice, and cereals
Iron-Rich Foods listed by Quantity/Approximate Iron Content in milligrams:
- Oysters — 3 ounces/13.2 mg
- Beef liver — 3 ounces/7.5 mg
- Prune juice — 1/2 cup/5.2 mg
- Clams — 2 ounces/4.2 mg
- Walnuts — 1/2 cup/>3.75 mg
- Ground beef — 3 ounces/3.0 mg
- Chickpeas — 1/2 cup/3.0 mg
- Bran flakes — 1/2 cup/2.8 mg
- Pork roast — 3 ounces/2.7 mg
- Cashew nuts — 1/2 cup/2.65 mg
- Shrimp — 3 ounces/2.6 mg
- Raisins — 1/2 cup/2.55 mg
- Sardines — 3 ounces/2.5 mg
- Spinach — 1/2 cup/2.4 mg
- Lima beans — 1/2 cup/2.3 mg
- Kidney beans — Turkey, dark meat — 3 ounces/2.0 mg
- Prunes — 1/2 cup/1.9 mg
- Roast beef — 3 ounces/1.8 mg
- Green peas — Peanuts — 1/2 cup/1.5 mg
- Potato — 1 potato/1.1 mg
- Sweet potato — 1/2 cup/1.0 mg
- Green beans — 1/2 cup/1.0 mg
- Egg — 1 egg/1.0 mg
Reviewed by Chun H. Yin, MD, FAAP