What is iron deficiency?
Iron deficiency is when there is not enough iron in the body.
Iron is an essential mineral that is needed to produce red blood cells, which are important for a healthy immune system, mental function, muscle strength and energy. Its main role is in red blood cells, where it helps make a protein called haemoglobin. Haemoglobin carries oxygen in the blood from the lungs to all the cells in the body so they can work properly.
The body can’t make iron, so you need to get it from food. If you do not eat as much iron as you use each day, you develop iron deficiency.
It is important to have the correct amount of iron in the body. If you have low iron, you can develop anaemia. If you have too much iron, it can be toxic. Iron deficiency is the most common nutritional disorder in the world.
Need help getting enough iron?
Check out this infographic to ensure you get an adequate iron intake with a balanced diet.
Learn how much iron you need each day, which foods are the best sources of iron and how to incorporate them in your diet.
What are the symptoms of iron deficiency?
If you have iron deficiency, you may not realise it as you may just feel tired and run down.
Low iron symptoms include:
- feeling tired, listless and weak
- poor memory and concentration
- poor performance at school or work
- getting infections
- finding it difficult to do aerobic exercise
- fatigue (feeling very tired)
- behaviour problems in children
- decreased libido (sex drive)
These symptoms can also be caused by other conditions.
What causes iron deficiency?
There are 3 main causes of iron deficiency.
- Not eating enough iron-rich foods. Your body can store iron but it cannot make it. Iron must come from food. Some people need more iron than others. The people who need most iron are children, teenagers (especially girls), females who have periods, pregnant women and breastfeeding women. Babies need breast milk or iron-fortified formula for the first year. Babies who have cow's milk instead are more likely to get iron deficiency. People who follow vegetarian or vegan diets are also more at risk.
- Trouble absorbing iron. Iron in food is absorbed through the stomach and bowel. Some health conditions affect how much iron is absorbed, such as coeliac disease. If you’ve had stomach surgery, that can also affect how much iron you can absorb.
- Blood loss. If you lose blood through any sort of bleeding, this means you lose iron too. The main causes of excess blood loss are having heavy menstrual periods and bleeding in the stomach or bowel, which may be associated with taking medicines such as aspirin or other anti-inflammatory medicines, ulcers, bowel polyps or cancer. Other causes can include giving blood too regularly, losing blood due to surgery, some gut conditions such as inflammatory bowel disease, and infection with parasites such as hookworms.
When should I see my doctor?
If you think you might have low iron levels, see your doctor. It’s important to find out why you have iron deficiency and what you can do about it.
Make sure you see your doctor before taking any iron supplements, to get their advice on the right type of iron and dose for your needs.
See your doctor if you have any of the symptoms of anaemia, which include:
- being extremely tired and weak
- being short of breath
- your heart beating fast and irregularly, or both
- being dizzy and light-headed
- cold hands and feet
- sore or inflamed tongue
- brittle nails
- poor appetite
- being irritable
- having cravings for unusual things like ice, dirt or starch
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How is iron deficiency diagnosed?
To confirm whether you have iron deficiency, your doctor will talk to you and examine you. The only reliable way of telling if you are iron deficient is through a blood test to look at your iron levels and to check for anaemia. You may also need other tests to find out what is causing the iron deficiency.
How is iron deficiency treated?
First your doctor may investigate to find the cause of the iron deficiency. This is to check whether a serious disease could potentially be causing the problem. If your doctor finds a cause, you will need the right treatment for that cause.
The second step is to bring the iron levels back to normal. This can be done a number of different ways. Depending on your needs, your doctor may recommend that you:
- eat more foods high in iron
- eat more foods containing vitamin C to help you absorb iron better
- consume less foods and drinks that stop you absorbing iron, like calcium, fibre, tea, coffee and wine
- take iron tablets or liquid iron supplements
- have an intravenous infusion of iron or (in extreme cases) a blood transfusion
If you take iron supplements, you will need to take them for several months and possibly longer. They may make your stools (poo) dark, and can also cause constipation, so your doctor may suggest you take a stool-softener to help with this. You should only take iron supplements under medical supervision as you could poison yourself if you take more than the recommended dose and they can also interfere with other minerals in your body as well as your immune system.
Can iron deficiency be prevented?
Most people can prevent iron deficiency by consuming enough iron in their diet. Check out this infographic for an iron levels chart of how much iron you need each day, which foods are the best sources of iron and how to incorporate them in your diet.
Complications of iron deficiency
Iron deficiency can cause:
- anaemia (when there are too few red blood cells or haemoglobin in the blood is below normal because of too little iron)
- an impaired immune system
- poorer aerobic sports performance
- premature delivery and low birth weight baby
- problems with motor and mental function in babies
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Last reviewed: January 2021