Family doctor

Overview:

• Iron deficiency is the most common dietary deficiency in the world
• It may also indicate a serious underlying disease causing blood loss (e.g. bowel cancer)
• Iron deficiency anaemia causes developmental and learning problems in children
• Symptoms include tiredness, lack of concentration and problems fighting infections
• Iron deficiency is more common among children, women, and pregnant women
• Blood tests are used to diagnose the condition
• Further tests may be needed to determine the exact cause
• Iron tablets or syrup is used to treat iron deficiency
• It can be prevented by having enough iron in the diet
• Red meat is a good source of iron. Vegetables with iron are not well absorbed

What is it?

Iron deficiency anaemia is a condition which causes a decrease of red blood cells in the blood. However, iron deficiency can be present before actual anaemia develops. Actual anaemia only develops once iron deficiency becomes more severe.

It is caused by a lack of iron in the diet, poor iron absorption in the body, or from blood loss, for example, by heavy menstrual bleeding or from bleeding from the bowel e.g. ulcer or bowel cancer.

It is also caused by lead poisoning in children.

In young patients it is more likely to be caused by poor intake in the diet. In older patients there is more likely to be an underlying cause of blood loss and this should be investigated by further tests.

It is the most common diet deficiency around the world. Research shows many women and children do not have enough iron in their diet.

Up to 25 percent of three year olds have iron-deficiency anaemia. In addition, 20 percent of women, 50 percent of pregnant women and three percent of men are iron deficient. A total of 15 percent of the population worldwide have iron deficiency anaemia.

Iron in the body is used to carry oxygen to cells and to help fight infections. It is essential for a child's growth and learning ability.

Anaemia develops slowly over time after iron stores have been depleted in the body.

You need larger amounts of iron at certain times in you life. Infants, children and teenagers need more because they are growing. Pregnant women, women who have periods, athletes, and vegetarians also need an adequate iron intake.

Babies are born with high iron stores in the liver which is enough to last for about four to six months of breast feeding or formula feeding. Additional iron is needed at about six months when iron-fortified baby cereal is introduced, followed by other solids. Premature babies may deplete their iron stores sooner than other infants.

Women need more iron because their iron stores are depleted during menstruation.

Babies up to 12 months need 9 mg of iron a day, children up to 11 years need 6 to 8 mg of iron, teenagers need 10 to 13 mg, women need 12 to 16 mg, and pregnant women need 22 to 36 mg. Adult men need the least at 7 mg a day.

Diagnosis

This is made on the basis of a blood test which will show iron deficiency or depleted body iron stores. If this is severe, it will have led to anaemia with a lower than normal haemoglobin (red blood cell) level.

Iron deficiency anaemia is not a complete diagnosis in itself and an underlying cause should be sought. Recent studies have shown that is may be particularly dangerous to attribute iron deficiency solely to menstruation in women over 40, as there could also be a source of blood loss from the bowel.

Your doctor will usually base the decision on whether further investigation is needed, on the patients age and other symptoms.

For example, an otherwise healthy vegetarian woman of 20 with heavy periods, can probably assume that iron deficiency is a combination of limited intake and heavy iron loss and further tests may not be needed if the deficiency corrects itself with treatment.

In contrast, an older patient (usually over 40), with symptoms of bowel problems would need a full investigation to determine the cause of the blood loss (with gastroscopy and colonoscopy).

What are the symptoms?

Note: early and mild iron deficiency and anaemia may cause no noticeable symptoms in many people.

If there is not enough iron in the blood you may feel tired and cold, have problems concentrating, are more prone to infection, and find it difficult to learn. Naturally many other things could cause similar symptoms.

Children may experience long-term learning difficulties if they are iron deficient. They may have problems with stunted growth, a lack of appetite, and lack of fitness.

Iron deficiency anaemia for more than three months is associated with more learning problems than anaemia for less than three months.

Iron deficiency can lead to anaemia and shortness or breath and dizziness. Usually a significant degree of anaemia is needed to cause symptoms like these.

Blood tests to assess a person's serum ferritin level, red cell blood count and iron saturation, are used to diagnose the condition.

Sometimes there will be symptoms of the underlying problem which has caused the iron deficiency e.g. heavy periods or bleeding from the bowels.

What is the treatment?

It is important to have a full understanding of the condition which has caused the problem as that will determine what other treatments may be needed apart from simply replacing iron.

For example, specific treatment for heavy periods, a stomach ulcer or bowel cancer may be needed.

Iron supplements are necessary to rebuild a person's iron count. Adults can take iron tablets and children can be given an iron syrup such as ferrous gluconate.

The syrup can be given with a drink containing vitamin C, and should be taken for three months.

Side effects from iron supplements include constipation and other intestinal upsets. A large overdose can be fatal.

Studies have shown that developmental delays in children from lack of iron are not repaired from a higher iron intake.

Eating iron-rich foods that are well absorbed can also help.

How can dietary iron deficiency be prevented?

Having enough iron in the diet is the best way to prevent this form of anaemia.

Many foods contain iron but many are not well absorbed such as spinach.

Haem iron is the easiest iron for the body to absorb. This is found in red meat such as beef and lamb. Smaller amounts are found in pork, chicken and fish. As a general rule the redder the meat, the higher the iron content.

Non-haem iron is about 10 times harder for the body to absorb. This form of iron is found in foods such as bread, breakfast cereals, beans and nuts. Absorption can be improved by eating it with foods rich in vitamin C like citrus fruit, broccoli, tomatoes and capsicum.

Adding meat to a meal will also increase the absorption of non-haem iron.

Coffee, tea and milk can prevent absorption of iron. Do not have these drinks with meals. Do not give cow's milk to a baby under 12 months or tea to a preschooler.

Getting help

Your doctor, practice nurse or dietitian will be able to help.