Iron Deficiency Anaemia
Iron deficiency anaemia is the most common dietary deficiency in the world and particularly affects children, women and pregnant women. In New Zealand it is estimated that up to 25% of children under the age of three years have some degree of iron deficiency. It is further estimated that up to 20% of New Zealand women and 3% of New Zealand men are iron deficient.
Anaemia is a deficiency of haemoglobin - a protein attached to red blood cells that’s essential for carrying oxygen around the body. It is due to either a lack of red blood cells and/or their haemoglobin content. Iron deficiency is the most common cause of anaemia. Without enough iron, the body cannot produce enough haemoglobin.
Iron deficiency anaemia is caused either by not consuming enough iron-containing food, poor absorption of iron by the body, or loss of iron due to bleeding.
Babies are born with sufficient iron supplies to last for approximately six months of feeding with milk (breast or formula) alone. After this time they need iron fortified and iron rich foods gradually added to their diets to meet their iron requirements.
Children and teenagers go through spurts of rapid growth, which requires a great deal of iron. A balanced diet, with adequate amounts of iron is important at these times.
Iron deficiency anaemia occurs frequently among women of childbearing age. In women who are not pregnant the cause may be due to heavy loss of blood during menstruation. In pregnant women, iron stores have to serve the increased blood volume of the mother, as well as the needs of the growing baby. If sufficient iron intake is not maintained (either in the diet or in the form of iron supplements), iron deficiency anaemia can result.
In men and women a cause of iron deficiency anaemia is blood loss from the digestive tract. . Blood loss from the digestive tract can occur as a result of long-term use of aspirin, gastric ulcers, duodenal ulcers, bowel cancer, or other conditions.
The symptoms of iron deficiency anaemia tend to appear gradually. Symptoms may include:
- Fatigue
- Weakness
- Paleness of the skin, gums and nail beds
- Reduced ability to fight infections
- Difficulty concentrating
- Headaches
- Shortness of breath when exercising
- Angina (heart related chest pain)
Long-term iron deficiency may cause developmental and learning problems in children. When iron deficiency is severe, inflammation of the tongue (glossitis) and abnormal growth of the fingernails may occur.
An assessment of symptoms and blood tests are used to diagnose iron deficiency anaemia. When it is suspected that there is blood loss from the digestive tract, tests to detect blood in the bowel motions may be recommended. Diagnostic tests (eg: colonoscopy, gastroscopy) to investigate the digestive tract for the source of any blood loss may be performed.
It is important that the underlying cause of the deficiency is identified, as iron deficiency may be the first symptom of a more serious disorder.
Treatment of iron deficiency anaemia will depend on the underlying cause of the deficiency.
Iron supplements may be prescribed and/or a change in diet recommended. In persons who have poor absorption of iron through their digestive systems (eg: coeliac disease) regular iron injections may be prescribed. In cases where the anaemia is severe, a transfusion of red blood cells may be required.
If the underlying reason for iron deficiency is loss of blood from the digestive tract, treatment with medications or surgery may be required.
The best way to prevent iron deficiency anaemia is to have sufficient iron in the diet. There are two main types of dietary iron: haem iron and non-haem iron.
Sources of haem iron include liver, red meat, chicken and fish. Haem iron is readily absorbed by the body.
Non-haem iron is found in whole grain cereals, vegetables (especially leafy green vegetables), fruits, nuts and legumes. This type of iron is not as readily absorbed as haem iron. To assist the body to more readily absorb non-haem iron, the following is recommended:
- Include a source of vitamin C with a meal
- Consume meat with non-haem iron food
- Avoid tea and coffee at meal times.
The recommended daily dietary intake of iron is:
Infants 7-12 months 9mg
Children 1-11 years 6 - 8mg
Teenagers 12–18 years 10 - 13mg
Women 19–54 years 12 - 16mg
Women 54 yrs + 5 - 7mg
Men 19 + years 7mg
To put these quantities in some kind of perspective, a 250 gram beef steak may contain around 10mg of iron, a baked potato with skin around 2mg, and a chicken leg between 1 and 2mg.
Eating plenty of iron containing foods is particularly important for children and pregnant or menstruating women. People who are strict vegetarians (particularly vegans), and people on weight reduction diets or rigorous exercise programs also need to make sure they are getting a good source of iron in their dietary intake and/or in the form of iron supplements.
Anderson, K.N., Anderson, L.E. & Glanze, W.D. (eds.) (2006) Mosby’s medical, nursing, & allied health dictionary (6th ed.) St. Louis: Mosby-Year Book, Inc.
Brody, T. (2006) Iron Deficiency Anemia. The Gale Encyclopedia of Medicine. Third Edition. Jacqueline L. Longe, Editor. Farmington Mills, MI. Thompson Gale.
Everybody (2006). Iron Deficiency. Auckland: MediMedia (NZ) Ltd
Last Reviewed - 24/7/07
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