Iron

Definition

Iron is an essential nutrient that performs a wide range of functions in the body, including assisting in the transport of oxygen via the blood.

Description

Iron is an essential part of haemoglobin, a substance inside red blood cells that is designed to carry oxygen around the body. This is essential in providing energy for daily life. Myoglobin contains iron and causes the red colour in muscles. Myoglobin is a protein that helps store oxygen in muscle tissue. Iron is an essential part of many enzymes, including those involved in energy production. Enzymes are the catalysts that drive many cell functions. Our immune system relies on iron to effectively fight infection.

Signs and symptoms

The most common symptoms of iron deficiency anaemia include:

• Tiredness
• Lethargy (lack of energy)
• Shortness of breath (dyspnoea)

Less common symptoms include:

• Headache 
• Tinnitus – a noise heard in one or both ears such as a ringing in your ears
• Altered taste
• Pica - a desire to eat non-food items, such as ice, chalk, paper or clay
• Sore tongue
• Feeling itchy 
• Hair loss
• Difficulty swallowing

Deficiency

About one third of the world's population is iron deficient.  It is thought that up to five per cent of the Australian population has iron deficiency anaemia. Menstruating women at greater risk than men and postmenopausal women. Iron deficiency can occur through inadequate dietary Iron intake, through menstruation, sweat and blood loss or conditions that restrict the body's ability to absorb iron e.g coeliac and Crohn's disease.

TOO MUCH IRON

The body stores iron very efficiently and it is possible to have too much iron in the body which can be toxic. Haemochromatosis is a condition linked to heart disease and some cancers that is characterised by excessive iron stores. Treatment includes limiting the amount of iron in the diet and regularly removing blood until iron levels normalise.

Sources

The two types of iron include:

• Haem iron is found in animal foods such as beef, lamb, chicken, egg yolks and fish. Offal products such as liver and kidney are particularly rich in haem iron. Pregnant women should avoid eating too much offal as it contains large amounts of vitamin A which can cause birth defects. Haem iron is easily absorbed by the body. 

• Non-haem iron is found in plant foods such as dried beans and lentils. Good vegetarian sources of non-haem iron include iron-fortified breakfast cereals, flours and whole grains. Red meat also contains non-haem iron. Non-haem iron is not absorbed by the body as efficiently as haem-iron.

Dosage

Most people need to absorb just a small amount of iron each day to stay healthy (around 1 mg for adult males and 1.5 mg for menstruating females). As our bodies don't absorb all the iron from the foods eat, we need to consume  several times that amount.

Treatment for iron deficiency anaemia usually involves taking iron supplements to replace missing iron while making dietary and lifestyle changes to address the underlying cause. Your GP will advise you about the most suitable type and dosage of iron for you.

Cautions

Storing iron supplements
If you have young children, it is important to store iron supplements out of their reach. This is because an overdose of iron supplements in a young child can be fatal.