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Iron deficiency and your immune system

Illustration of red blood cells
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Did you know iron is really important for our immune systems? Iron is a metallic element and a key nutrient for the human body. It helps to make haemoglobin, the protein in red blood cells that carries oxygen around the body.

If you can’t get enough iron, you’re at risk of developing iron deficiency anaemia. This has all kinds of implications for your health, and in particular for your immune system.

What causes an iron deficiency?

A serious iron deficiency is nearly always caused by one of the following:

  • Heavy periods
  • Pregnancy
  • Bleeding in the gastrointestinal tract caused by e.g. stomach cancer, stomach ulcers, non-steroidal anti-inflammatories
  • Chronic kidney disease

Some other causes of iron deficiency include inflammatory bowel disease, oesophagitis, and donating blood.

Can a poor diet contribute to iron deficiency?

It’s rare for iron deficiency anaemia to be caused solely by a lack of iron in your diet.

However, if you eat a low-iron diet AND you have one of the conditions listed above, you may be more likely to develop iron deficiency anaemia. For instance, if you’re pregnant and not eating enough iron in your diet, you might develop anaemia.

What happens to my immune system if I get an iron deficiency?

In the short term, you might experience symptoms like tiredness, lack of energy, shortness of breath, heart palpitations and pale skin.

In the long term, untreated iron deficiency anaemia might cause more serious complications, including weakening the immune system. If this happens, you’ll be more likely to get infections.

Another suspected complication relates to vaccinations like the flu jab and the COVID-19 vaccine. This study has shown that an immune system weakened by iron deficiency anaemia appears to be less effective in responding effectively to vaccines.

You can learn more about the link between iron levels, the immune system and vaccination by watching this video featuring Professor Luke O’Neill, a specialist in biochemistry. If you’re worried about your iron levels speak to your GP or one of our pharmacists.

In addition to immune system problems, iron deficiency anaemia can cause issues with the heart and lungs, including tachycardia (a very fast heart rate) and heart failure. It can also cause complications in pregnancy.

How can I get more iron?

If you’ve got a condition that’s causing anaemia, your GP might prescribe iron tablets. These aren’t the same as supplements you might buy in a health food shop or supermarket – they’re much richer in iron, which means they can have some side effects like constipation, diarrhoea and feeling sick.

Iron-rich foods

A simple way to get more iron is to eat foods rich in iron. If you’re iron deficient, your GP might recommend that you start eating more:

  • Dark leafy vegetables like curly kale
  • Red meat
  • Kidney beans, chickpeas, edamame beans and lentils
  • Nuts
  • Dried fruit
  • Breakfast cereal fortified with iron
  • Soy bean flour

Another good source of iron is liver, but this isn’t suitable for pregnant women.

In addition to eating more of these foods, you might need to have less tea, coffee, dairy products and wholegrain cereals. Consuming too much of these can make it hard for your body to absorb iron.

Iron supplements

If you struggle to get enough iron through your diet alone, you can take iron supplements. This might be an option if you’re on a restricted diet or have allergies that make it hard for you to have a varied and balanced diet.

Iron supplements are safe to take, but you shouldn’t have more than 17 milligrams (mg) each day, unless you’ve been told otherwise by a doctor. You won’t need iron supplements if you’ve already been prescribed iron tablets.

Shop iron supplements

How can I help my immune system?

Lots of things contribute to a healthy immune system. Generally speaking, to have a healthy, happy body that can fight off infection, you should try to do the following: