Iron is an essential mineral that our bodies need for everyday health. It's particularly important for making haemoglobin, the protein in red blood cells that helps transport oxygen around the body.
Iron also contributes to normal energy production, cognitive function and immune function, as well as helping to reduce tiredness and fatigue.
Our bodies can't make iron, so we need to get it through our diet. For some people, an iron supplement may also be recommended. Here's what iron does, where to find it and what to consider if you're concerned about getting enough.
What Is Iron?
Iron is an essential mineral found naturally in many foods, as well as in fortified foods and supplements. Although we only need relatively small amounts, iron is involved in several important processes throughout the body.
One of its best-known roles is helping the body produce haemoglobin, a protein found in red blood cells. Haemoglobin contains iron and helps carry oxygen from the lungs to tissues throughout the body. Iron also helps your body release energy from food and plays an important role in supporting normal brain and immune function.
What Does Iron Do in the Body?
Iron has several recognised functions in the body.
1. Iron Helps Carry Oxygen Around the Body
One of iron's most important jobs is helping to make red blood cells and haemoglobin. Haemoglobin is the protein that carries oxygen from your lungs through your bloodstream to the rest of your body.
Iron is also found in myoglobin, a protein that helps supply oxygen to your muscles. In this way, getting enough iron helps support normal oxygen transport throughout the body.
2. Iron Helps Your Body Release Energy From Food
Iron plays an important role in the way your body releases and uses energy from the food you eat. It also contributes to the reduction of tiredness and fatigue.
That doesn't mean feeling tired automatically means you're low in iron. Fatigue can have many different causes, so persistent or unexplained tiredness is worth discussing with your doctor rather than simply reaching for an iron supplement.
3. Iron Supports Brain Function
Iron also supports normal cognitive function – in other words, the everyday processes your brain uses for things like thinking, learning, memory and concentration. It's one of several essential nutrients your brain needs as part of a healthy, balanced diet.
4. Iron Supports Your Immune System
Iron plays a role in supporting the normal function of your immune system. Alongside other essential vitamins and minerals, getting enough iron through a balanced diet helps provide your body with the nutrients it needs to function normally.
5. Iron Plays a Role in Cell Division
Iron also has a role in normal cell division – the natural process through which cells reproduce as the body grows, renews and maintains its tissues.
Why Do We Need Iron?
Our bodies can't make iron, so we need to get it from the foods we eat. How much we need isn't the same for everyone. Iron needs vary depending on factors such as age and life stage, and can be higher for people who regularly lose blood through menstruation. Requirements also change during pregnancy.
For most of us, the best place to start is with a varied, balanced diet containing plenty of iron-rich foods. If you're concerned that you may not be getting enough, it's worth speaking to a healthcare professional before reaching for a supplement.
What Foods Contain Iron?
Iron is naturally found in a wide range of foods, so there are plenty of ways to include it in your diet. Good sources of iron include:
- red meat
- poultry
- fish and shellfish
- beans and lentils
- tofu
- nuts and seeds
- dark green leafy vegetables
- dried fruit
- fortified breakfast cereals and breads
You'll often hear iron described as either heme iron or non-heme iron. The difference simply refers to where the iron comes from and how easily our bodies can absorb it.
What Is Heme Iron?
Heme iron comes from animal foods, including meat, poultry and seafood. This form of iron is generally easier for our bodies to absorb.
What Is Non-Heme Iron?
Non-heme iron is the form found in plant foods such as beans, lentils, tofu, nuts, seeds and green leafy vegetables, as well as some fortified foods.
Our bodies don't absorb non-heme iron quite as easily as heme iron, but that doesn't mean plant-based foods can't make a valuable contribution to your iron intake. What you eat alongside them can also help.
For more inspiration, take a look at our guide to iron-rich foods.
How Can You Help Your Body Absorb Iron?
Getting enough iron isn't only about how much is on your plate – how well your body absorbs it matters too. One simple way to help is to pair plant-based sources of iron with foods containing vitamin C, which helps your body absorb iron.
That could be as easy as:
- adding tomatoes or peppers to a lentil dish
- topping fortified cereal with berries
- adding peppers or a squeeze of lemon to leafy greens
- serving beans with tomatoes
Your cup of tea or coffee is worth thinking about too. Both contain natural compounds that can make it harder for your body to absorb iron when they're consumed with a meal. If you're trying to increase your iron intake, you may prefer to enjoy tea and coffee between meals instead.
How Much Iron Do I Need?
There's no single answer to this because our iron needs change throughout life. People who menstruate generally need more iron because some is lost through menstrual blood. Requirements also change during pregnancy, while needs are different again after menopause.
Your diet matters too. Because the iron found in plant foods isn't absorbed as readily as the iron in animal foods, people following vegetarian or vegan diets may need to pay particular attention to including plenty of iron-rich foods.
If you're concerned about your iron intake or think your levels may be low, it's better to get individual advice than to simply start taking more iron.
What Happens If You Don't Get Enough Iron?
If your body isn't getting or absorbing enough iron over time, its iron stores can gradually become depleted. Eventually, this can lead to iron deficiency, and if it progresses, iron-deficiency anaemia.
Tiredness and weakness are often associated with low iron, but these symptoms can have lots of other causes too. That's why it's not a good idea to assume that feeling tired means you need an iron supplement.
If low iron is suspected, a healthcare professional can arrange appropriate blood tests. These may include looking at haemoglobin and ferritin, which can help build a clearer picture of your iron status.
If you've been diagnosed with iron deficiency or iron-deficiency anaemia, follow the treatment and supplementation advice you've been given rather than trying to manage it yourself.
Do I Need an Iron Supplement?
Not necessarily. Many people can get the iron they need through a varied, balanced diet. There are times, however, when additional iron may be recommended. If you're choosing a supplement, you'll find iron in lots of different forms, including tablets, capsules, liquids, drops and tonics.
You'll also come across different types of iron. Iron bisglycinate, for example, is commonly used in products described as gentle iron, while other supplements use different iron compounds.
When comparing products, look at how much actual – or elemental – iron the recommended serving provides. This gives you a more useful comparison than simply looking at the overall weight of the iron compound.
You can explore our iron supplements range to compare tablets, capsules, gentle iron, liquid iron and iron tonics from trusted brands.
What About Iron Supplements for Women?
Iron is often particularly associated with women's health because menstruation increases iron requirements. But not every woman needs an iron supplement, and iron needs change throughout life. Someone who menstruates may have different requirements from someone who is pregnant or has been through menopause.
So rather than choosing a supplement simply because it says “for women” on the label, consider the form and amount of iron it provides and whether supplementation is appropriate for you. If you're pregnant, planning a pregnancy or concerned that your iron levels may be low, speak to your doctor, midwife or another suitably qualified healthcare professional for individual advice.
Can You Take Too Much Iron?
Yes. When it comes to iron, more isn't always better. Unlike some nutrients, taking more iron than you need isn't something to aim for. Iron supplements should always be taken according to the directions on the product or the advice of a healthcare professional, particularly when using higher-dose supplements.
And an important practical point: always keep iron supplements safely out of the reach of children.
The Evergreen View
Iron might be a micronutrient, but it has some big jobs to do. It helps carry oxygen around the body, helps us release energy from food and supports normal brain and immune function. It can also help with the reduction of tiredness and fatigue.
For most people, food is the best place to start. A varied diet that includes plenty of iron-rich foods – and vitamin C alongside plant sources of iron – can help you make the most of the iron you're eating.
And if you're feeling unusually tired or think your iron levels might be low, don't assume that taking more iron is automatically the answer. Finding out what's going on first can help you make a more informed choice about whether supplementation is right for you.
For more help, explore our iron supplements or head to our guide to iron-rich foods for more ideas on getting iron through your diet.
Updated 22nd September 2026
