Iron: what it is, why it’s important & how to make sure you’re getting enough in your diet

During the winter months more people are paying attention to their health and taking steps to boost their immune system. But exercising regularly, getting enough sleep and drinking plenty of water can only do so much if your iron levels are low. Iron deficiency is the most common nutrient deficiency in the world, and many of us can have low iron stores without even knowing about it. If you’ve been feeling tired lately, or get out of breath going up the stairs – despite being physically fit – then it’s possible your iron levels may need a boost. But why exactly is iron so important and how can we make sure we get enough in our diet? 

1. What is iron?

Iron is an essential mineral that our body needs to function properly. Our bodies can’t produce iron, so we have to get it through our diet – either through foods that contain it naturally, or foods that are fortified with iron, like breads and cereals.

One of the main reasons that iron is so important to our health is because it’s a key ingredient of haemoglobin, a protein that’s found in red blood cells. Haemoglobin helps transport oxygen around the body, and it represents around two-thirds of all iron in our bodies. If we don’t have enough iron, we can’t produce enough healthy red blood cells, and our bodies can’t get enough oxygen. This means we’ll feel tired and lacking in energy – and, should this develop into the more serious iron deficiency known as anaemia, you might feel out of breath easily and can start experiencing fatigue and weakness.

Iron also plays an important role in supporting our immune system (to read more about boosting your immune system, have a read of our recent article on this topic). It also helps regulate body temperature, can improve athletic performance, and keeps our hair, skin and nails healthy. 

2. How much iron do we need?

The amount of iron we need depends on a person’s age and gender. For much of their lives, women need more iron than men because they lose blood (and iron rich Haemoglobin) each month when they menstruate – but this means that after menopause, a woman’s iron requirements drop and are the same as a man’s. The Recommended Daily Allowance (RDA) of iron for men and women over the age of 50 is 8.7 mg – rising to 14.8mg a day for women aged 19 to 50. However, there are some exceptions to this and you may need more iron if you:

  • Have an ulcer (these can cause blood loss)
  • Suffer from kidney failure (particularly if you’re undergoing dialysis, which can decrease iron stores)
  • Have a gastrointestinal disorder (e.g. coeliac disease or Crohn’s disease) that make it hard for your body to absorb iron
  • Take lots of antacids, which can prevent your body from absorbing iron
  • Have had weight loss surgery
  • Work out a lot (intensive exercise can damage red blood cells)

3. Which foods are the best sources of iron?

Like with most nutrients and essential minerals, the best way to get iron is through your diet where possible. There are lots of delicious and healthy meals you can make that are high in iron – you can have a look at some recipe ideas here. If you’re vegetarian, you might want to check out these iron-rich recipes, and if you’re vegan, this article features plant-based iron-rich recipes.

There are two different types of dietary iron – heme and non-heme – and they work in slightly different ways.

Heme iron

Heme iron is more easily absorbed by the body and can be found in animal products like red meat, fish including halibut, haddock, salmon or tuna; shellfish like clams, oysters and mussels; organ meat (like liver), and eggs.

Of all heme iron foods, the iron that’s found in red meat is the easiest for our bodies to absorb. The problem with this is that due to the increased risk of diabetes, heart disease and certain cancers linked to red meat, many people are trying to reduce their consumption of red meat, or cut it out altogether.

Non-heme iron

Non-heme iron is found in plants, and the best food sources include dried fruits like figs and apricots, dark green leafy vegetables, nuts and seeds, chickpeas, beans and pulses, and fortified breakfast cereals. The problem here is that our bodies don’t absorb as much iron from non-heme iron sources as they do from heme iron (although around 85–90% of total iron intake usually comes from the non-heme form). The good news however, is that non-heme iron rich foods usually come packed with plenty of antioxidants, anti-inflammatories, and vitamins, which help boost our immune system.

4. Which foods help you absorb more iron?

If you’re trying to cut back on the amount of red meat you’re eating, or you follow a plant-based diet, the good news is that there are several steps you can take to help your body absorb more iron than it would otherwise. While our bodies don’t all absorb iron in the same ways, some foods do make it easier – and others can have the opposite effect. So what do we need to know?

Vitamin C

Vitamin C has been proven to boost iron absorption from non-heme iron food. It collects the iron and stores it in a way that makes it easier for our bodies to absorb. Some studies suggest that eating foods high in vitamin C can increase iron absorption by 67%. Foods that are high in vitamin C include dark green leafy vegetables, peppers, broccoli, brussels sprouts, potatoes, strawberries, blackcurrants and citrus fruit. This means that eating vegetables containing plenty of vitamin C while you’re eating high-iron foods is always a good idea. Alternatively, you could have a glass of orange juice with a meal – but watch out for the sugar!

Vitamin A and Beta-Carotene

Vitamin A plays an important role in boosting your immune system and keeping your eyes and bones healthy. Beta-carotene is an orangey-red pigment that’s found in fruit and vegetables, and your body turns it into vitamin A. Foods that are high in beta-carotene and vitamin A include dark leafy greens, sweet potatoes, carrots, broccoli, butternut squash, peppers, cantaloupe melon, apricots, peas and lettuce. One study of people eating cereals that were fortified with iron found that consuming vitamin A alongside it increased absorption by up to 200%.


On the flipside, foods containing chemicals called polyphenols should ideally be avoided when eating high-iron foods. This is because polyphenols bind to the iron and make it less soluble, meaning it’s harder to absorb. Tea, coffee and wine are all high in polyphenols, and because these are often consumed with meals, we may not be getting as much iron as we think; drinking just one cup of tea with a meal can reduce iron absorption by 60–70%. If you enjoy tea or coffee with breakfast, it’s best to wait at least half an hour after you’ve eaten to have your drink, and enjoy a glass of orange juice with your breakfast instead. Similarly, if you like to drink wine with dinner, it’s best to try to wait a while before pouring yourself a glass, to make sure you absorb as much iron as possible.

5. Should I take an iron supplement?

Low iron levels are common, and if you think you might have low levels, it’s best to visit your GP and get your blood checked. Very low iron levels can also indicate a more serious condition, such as an ulcer or other forms of blood loss, so it’s important to get your levels tested regularly so a doctor can investigate both the causes, as well as recommending appropriate treatment.

Low iron levels aren’t always easy to spot, but if left untreated, can lead to more serious health complications. The most common blood tests used to identify iron deficiency are haemoglobin and hematocrit tests, but because these aren’t that sensitive, they can usually identify whether you’re deficient in iron, but not always whether your iron stores are low. Due to the importance of identifying low iron levels early, if you can it’s worth asking your GP to have a ferritin test as well as a haemoglobin and hematocrit test, as this combination is most effective at identifying the early stages of low iron levels.

If you’ve tried making changes to your diet but your iron levels are still low, you may want to consider taking iron supplements. If you have especially low iron levels, your GP may suggest that you begin taking supplements immediately – and because they can produce results faster than changes to diet, they’re often the preferred choice of treatment for iron deficiency. Once you start taking iron supplements, you should ensure your blood is regularly tested, so you can see whether your iron levels increase or not and ensure you don’t end up taking too much.

Iron supplements come as tablets, capsules or as a liquid that you swallow. You can get these on prescription, or you can buy them from pharmacies, supermarkets, or health food shops both locally or online. Holland and Barratt as a wide range of iron supplements, which you can find here*. Or, even Amazon has a good selection that come in varying strengths. When comparing supplements, be sure to check the amount of elemental iron – this is the amount of iron that’s actually available for absorption. Your GP should be able to tell you the exact dose you need and may even suggest a particular supplement.

According to the NHS, unless you have extremely low iron levels, you shouldn’t take more than 17mg or iron supplements a day, unless advised by your doctor. This is because if you frequently take more than 20mg of iron a day, there can be possible side effects. These often include stomach upsets like nausea, vomiting, diarrhea, or constipation. Be sure to keep any iron supplements out of reach of young children and grandchildren too, as iron overdosing can be fatal for young children.

People who have the inherited condition hemochromatosis also need to be particularly cautious of taking iron supplements as while most people only absorb around 10% of all the iron they consume, people with hemochromatosis absorb up to 30%, which means that their iron stores can be raised to dangerous levels.

Final thoughts...

Iron is a key mineral that our bodies need to function. It’s also enormously important for maintaining the health of our immune system. While most people can get enough iron from eating a healthy, balanced diet, people with certain medical conditions may be more prone to low iron levels, and may need to take iron supplements to ensure their levels are high enough.

If you’re worried about your iron levels, it’s important to speak to your GP as soon as possible. As with most things, the sooner you detect low iron levels, the easier it will be to rectify.

Have you suffered from low iron levels – or do you have experience taking iron supplements? Join the health conversation on the community or leave us a comment below.

Links with an * by them are affiliate links which help Rest Less stay free to use as they can result in a payment or benefit to us. You can read more on how we make money here.


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