Iron-Deficiency Anemia
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
Definition
Iron-deficiency anemia results from reduced iron stores in the blood. This happens when there is not enough dietary iron to replace the iron used to produce hemoglobin. Hemoglobin is the component of red blood cells that carries oxygen to the tissues and muscles. Excess bleeding is another cause.
Causes
Causes include:
- Iron that is poorly absorbed in the digestive tract (may occur due to pica, hookworm, prior intestinal diseases or surgery)
- Chronic bleeding, including heavy menstrual bleeding
- Prolonged bleeding from hemorrhoids, ulcers, cancer, and bowel inflammations
- Inadequate iron in the diet
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
- Rapid growth cycles (infancy, adolescence)
- Heavy menstrual bleeding
- Pregnancy
- Diets that contain insufficient iron (fairly rare in the United States)
- Breast-fed infants that take no solid food
- Alcoholism
Symptoms
Symptoms include:
- Fatigue
- Increased skin pallor
- Fingernail changes
- Weakness
- Headache
- Decreased work capacity
- Heart palpitations
- Inability to stay warm
- Decreased resistance to infection
- Hair loss
- Shortness of breath during or after physical activity
Diagnosis
The doctor will ask about your symptoms and medical history, and perform a physical exam.
Tests may include:
- Serum iron
- Transferrin iron binding capacity
- Serum ferritin level
- Microscope examination of a blood smear
- Fecal occult blood test – looks for hidden blood in your stool
Treatment
Treatments may include:
Iron Supplements
Iron can be taken as an individual supplement or as part of a mulitvitamin. Iron comes in many "salt" forms. Ferrous salts are better absorbed than ferric salts. Ferrous sulfate is the cheapest and most commonly used iron salt. Some products contain vitamin C to improve iron absorption. Sustained-release or enteric-coated products may cause less stomach irritation than other products, but may be poorly absorbed.
Iron-Fortified Cereal
If your health care provider suspects that your breast-fed infant may be iron deficient, he or she may recommend that you add iron-fortified infant cereal to the baby's diet.
Prevention
A diet rich in iron can help prevent iron-deficiency anemia.
Iron in Food
The best sources of iron are liver, kidney, and red meats (heme iron). The iron from vegetable sources (non-heme iron) is less well absorbed than iron from animal foods. However, leafy greens such as spinach and kale are good vegetable sources. Lean meat, fish, or poultry eaten with beans or dark leafy greens can improve absorption of non-heme iron by a factor of three. Foods rich in vitamin C, such as citrus fruits and juices, increase iron absorption as does cooking foods in iron utensils.
Iron Availability of Foods
Some foods decrease iron absorption. Commercial black or pekoe teas contain substances that bind to iron so it cannot be used by the body. The amount of absorbable iron in a food is more important than the total iron content.
Iron for Infants
Full-term infants who are exclusively breastfed do not need supplemental iron until they are 6 months old. After 6 months old, breast-fed infants should receive extra iron in the form of iron-fortified infant cereals and juices rich in vitamin C. These infants should have an iron-fortified infant formula after they have been weaned from breast milk.
Term infants who are not breastfed are usually given an iron-fortified infant formula from birth. After 4 to 6 months of age, iron-fortified infant cereals provide a good additional source of iron.
Most medical guidelines recommend that premature infants receive an iron supplement by at least 8 weeks old and that it be continued until age 1. Iron-fortified formula for bottle-fed infants or commercial iron drops for breast-fed infants are the recommended source of supplemental iron.
Organizations
American Academy of Pediatrics
http://www.aap.org
American College Obstetrics and Gynecology
http://www.acog.org
SOURCES:
Guide to Clinical Preventive Services, 2nd ed. Williams & Wilkins, 1996.
Merck Manual of Medical Information, 17th ed. Merck & Co. Inc, 2001.
Last reviewed June 2001 by Medical Review Board
