Published November 22, 2012
Iron is an essential mineral we obtain from food. Most bodies contain about 2-4 grams of iron in total.1 It is mainly found in the body stored in red blood cells (haemoglobin,) it is also in the liver, spleen and bone marrow.
Why your body needs iron
Iron has many important roles within the body, including:
- Oxygen transportation – iron is required to transport energy, in the form of oxygen, around the body. Red blood cells contain haemoglobin which carries oxygen from the lungs to the rest of the body. Haemoglobin contains mostly iron and accounts for about two thirds of the body’s iron.
- Myoglobin support – myoglobin is a special protein that contains iron and is the reason that muscles are red in colour. Myoglobin helps store oxygen in muscle cells.
- Immune system support – inadequate iron intake may affect the functioning of the immune system.
- Supporting enzyme reactions – many enzymes in the body contain iron. Enzymes are required for many bodily processes to occur. For example, iron is required to make enzymes that are required for the production of energy from food.2 Iron is also required to make enzymes related to detoxification, making collagen and elastin and production of hormones and neurotransmitters.1
Health benefits of iron
Due to the many roles that iron performs within the body, it has wide ranging health benefits. Among its many health benefits, iron acts as a blood tonic to help maintain normal blood health through the formation of haemoglobin and red blood cells which transport oxygen to the tissues. It also helps maintain healthy brain function. Insufficient intake of iron can lead to symptoms such as muscle fatigue, headache and decreased general health and wellbeing.
Dietary sources of iron
Iron is found in a haem or non-haem form. The haem form of iron from food is absorbed by our bodies 2-3 times more easily than the non-haem form.1 Good sources of haem iron are animal-based, such as red meat, liver, kidneys, seafood and poultry. You can also obtain iron from non-meat sources (non-haem) such as whole grains, fortified cereals, beans, peas, lentils, nuts, seeds, green leafy vegetables and dried fruit. However, because the type of iron these foods contain is not as easily absorbed it is recommended that they are consumed with foods containing vitamin C to aid absorption. Vitamin C can help the body to absorb iron. This could, for example, be beans on toast with a glass of orange juice. Eating animal protein with iron from plant sources also helps iron absorption. Cooking also helps the absorption of iron from non-haem vegetarian sources. For example, only six per cent of the iron in raw broccoli is absorbed, whereas 30 percent is absorbed from cooked broccoli.2
Certain factors can also reduce the absorption of iron in the diet. These include:
- Tannins found in tea, coffee and wine bind to the iron and carry it out of the body. As such it is best to avoid these beverages if concerned about iron levels.
- Phytates and fibres in whole grains such as bran can reduce the absorption of many minerals including iron.
- Calcium and phosphorus can reduce the absorption of plant-sourced iron.2
Signs you may need more iron
Certain groups of people may be more at risk for dietary iron deficiency, for example when there is;
- Increased requirement for iron – this occurs during pregnancy and breastfeeding due to the increased blood volume. It also occurs during infancy and adolescence, due to the increased blood volume and growth. Additionally if toddlers and young children drink too much cow’s milk, the excess calcium may block some absorption of iron.
- Poor diet such as with alcoholics, ‘fad dieters’ or those with eating disorders.
- Vegetarians or vegan diets – due to inadequate intake of the more easily absorbable haem iron.1,2
Low dietary iron intake is common. Symptoms of inadequate iron intake may include (muscle) fatigue, headache, irritability, decreased general health and well-being. It can also affect concentration.1