Iron

What is Iron?

Iron is an important mineral the body needs for several processes, including growth and development. The body uses iron to make haemoglobin, the protein in red blood cells that’s responsible for transporting oxygen around the body, and for removing carbon dioxide^[1]. Haemoglobin also gives red blood cells their distinctive colour.

Iron is also stored in myoglobin, a protein in striated muscles, including your skeletal muscles. Myoglobin is important for accepting, storing, transporting, and releasing oxygen^[2].

Having adequate iron levels helps to support many functions, including:

• energy production

• physical performance

• immunity

• enzyme function

The human body cannot make iron, so you must get it from your food. Not having adequate iron levels can lead to anaemia. Too much iron can lead to toxicity, so it is essential to achieve balance. Iron absorption is a tightly controlled metabolic process that relies on special transport molecules in the first section of your small intestine. It is then transported around the body bound to the transporter protein transferrin^[3].

What’s the difference between ferritin and iron?

Ferritin and iron are not the same thing. Ferritin is one of the main iron storage proteins, releasing it when the body requires it. Whereas, iron is a mineral that’s important for making functioning red blood cells. It is a major component in the protein haemoglobin.

You can discover the differences between iron and ferritin in more detail in our blog: What’s the difference between ferritin and iron?

What is an Iron Blood Test?

An iron blood test can help you get a better understanding of your iron levels and whether they are within a healthy range. Iron tests are usually requested if it is thought your iron levels may be too high. Measuring stored iron levels in the form of ferritin is a better indicator of deficiency^[4]. However, measuring blood iron levels can be useful to screen for iron deficiency anaemia, especially if it is caused by a chronic illness^[5].

The benefits of checking your iron levels include:

• screening for deficiency or anaemia

• screening for toxicity or high levels

• monitoring the effectiveness of iron deficiency treatments

• understanding why you may be experiencing certain symptoms such as shortness of breath, fatigue, and reduced physical performance

What are Normal Iron Levels?

The normal reference range for iron will vary according to age, sex, and testing laboratory. Plus, serum iron levels can be influenced just by eating iron-rich food sources, so it is often considered alongside other biomarkers to give a clearer picture of your iron health.

*based on Forth laboratory reference ranges

What Impacts Iron Levels?

Because iron must be acquired from the diet and is integral to the normal production and function of red blood cells, several factors can impact its levels. Having too much or too little iron in your blood can have poor health consequences.

Causes of high iron levels

• Haemochromatosis

  An inherited condition which results in the build-up of iron over several years^[8]. Hereditary haemochromatosis is the most common cause of iron overload and is most prevalent in Caucasian people.

• Iron poisoning/toxicity

  If iron levels are high but ferritin and transferrin are normal it could indicate iron poisoning. Although rare, it is often caused by ingesting a large amount of iron all at once^[9] or persistent high dose supplementation.

The symptoms of high iron levels will depend on what’s causing them to be elevated. The symptoms of haemochromatosis and iron toxicity are shown below:

What causes low iron levels in the body?

Iron deficiency or iron deficiency anaemia is caused by a lack of iron in the blood. It is commonly caused by blood loss, such as:

• bleeding in your gastrointestinal tract

• bleeding in the urinary tract

• trauma or injury

• heavy menstrual periods

• frequent blood donation

• pregnancy

Iron deficiency can also be caused by a lack of iron in the diet, particularly if you are reliant on plant-based or non-haem iron sources, as these are not as well absorbed as haem iron found in animal products^[12].

Some conditions that affect iron absorption can cause low iron levels, including:

• coeliac disease

• inflammatory bowel disease

• Helicobacter pylori infection

• weight loss surgery

• rare genetic conditions

People who exercise frequently, including athletes, are at an increased risk of iron deficiency because regular exercise increases the demand for iron. For example, intense training increases the breakdown of red blood cells. Iron is also lost through sweat and iron absorption is lowered because of the inflammatory response to exercise^[13].

What are the symptoms of iron deficiency?

• fatigue

• weakness

• shortness of breath

• heart palpitations

• headaches

• pale skin

• sore tongue

• itchiness

• hair loss

• nail changes or deformities

• restless leg syndrome

• insomnia or difficulty sleeping^[14]

Managing Your Iron Levels

Keeping your iron levels within a normal range is important for the production of haemoglobin. It’s important to understand that iron needs change as we age. For example, women of menstruating age may need more iron to compensate for the losses that occur during their periods, compared to men and postmenopausal women.

Whether you need to increase or decrease your iron levels, here are some effective strategies to help.

How to increase iron levels

If you are deficient in iron, you may need to consult your doctor. They may suggest suitable treatments, such as iron tablets to help bring your levels back to normal. However, you should be able to support your iron levels with your diet by:

• Eating iron-rich foods

  It’s important to incorporate iron-rich foods into your meals. There are two types of dietary iron; haem and non-haem. Haem iron is naturally present in animal products, particularly red meat, liver, poultry, shellfish (clams, oysters, prawns) and fish. It is the most easily absorbed form of iron. Therefore, people who follow a vegan or vegetarian diet are at a greater risk of deficiency. Non-haem iron: is found in plant foods like spinach, green leafy vegetables, and fortified cereals.

• Increase absorption with vitamin C

  You can help to increase iron absorption by consuming vitamin C with iron-rich food sources, particularly non-haem iron. For example, drinking a glass of orange juice with a meal or drizzling lemon juice over a spinach salad will help increase iron absorption. Calcium-rich foods like dairy products or drinks that contain tannins, like tea and coffee, can inhibit iron absorption, so it is best to avoid these when eating iron-rich foods.

• Iron supplements

  Your doctor might prescribe iron tablets if you are deficient but you might also consider iron supplements if you do not get enough iron in your diet, for example, if you are vegan.

• Iron fish

  Cooking in cast iron cookware, or adding an ‘iron fish’ to your vegetable pot is a great way to add elemental iron into your diet. Iron from the fish or cookware slowly leaches into the food you’re cooking giving a steady and rich source of dietary iron. This was found to be how many hunter gatherer tribes got sufficient iron in their diet despite eating very low amounts of red meat^[15].

How to lower iron levels

If you’re iron levels are elevated, you might consider:

• Lowering iron-rich food consumption

  Foods that contain lots of iron may not be appropriate if you have high iron levels, particularly red meat and offal meats such as liver. Instead, you should focus on eating a healthy, balanced diet to ensure you get all the nutrients you need.

• Avoid vitamin C at meal times

  Vitamin C increases the absorption of iron, so it might be useful to avoid it with meals.

• Donate blood

  This is an effective way to help lower iron levels while doing something good. You might need to speak to your doctor to find out if it is safe for you to give blood.

• Stopping any iron containing supplements

  This is often the most common and most obvious cause of iron overload.

Written by Leanne Edermaniger

Based in the UK, Leanne specialises in writing about health, medicine, nutrition, and fitness.

She has over 5 years of experience in writing about health and lifestyle and has a BSc (hons) Biomedical Science and an MSc Science, Communication and Society.