Definition Iron is a trace mineral and is an essential nutrient. Iron is found in small amounts in every cell of the body. The body needs only small amounts. Iron is widely available in many foods.
What food source is the nutrient found in? Iron can be found in animals and plants. "Haeme" iron is found in animal products. This is the easiest form of iron for the body to use and absorb. About 15 to 35 percent of haeme iron gets absorbed in the body. "Non-haeme" iron is found in plant foods. The body has a harder time absorbing iron from plants. The body absorbs only 2 to 20 percent of non-haeme iron. Vegetarians must be sure to eat plenty of plant foods that are full of iron. Foods rich in vitamin C, such as citrus fruits, strawberries and broccoli, improve iron absorption, especially non-haeme iron.
Different foods have different amounts of iron. Some good sources of animal iron, or haeme iron, include:
(100g serve) lean beef = 2.2mg iron
(100g serve) liver = 9.5mg iron
(100g serve) lean lamb = 1.8mg iron
(100g serve) skinless chicken = 0.6 - 1.0mg iron
(100g serve) fish = 0.6mg iron
(100g serve) veal = 1.6mg iron
(100g serve) oysters = 3.9mg iron
Some good sources of plant iron, or non-haeme iron, include:
spinach (1/2 cup cooked) = 2.8 mg iron
kidney beans (1/2 cup) = 2 mg iron
potato, baked with skin (1 large) = 0.71mg iron
rice, brown (1 cup) = 0.9 mg iron
broccoli (1/2 cup) = 0.5 mg iron
egg (1) = 0.94 mg iron
breakfast cereal with added iron (1 cup) =3-4 mg iron
dried apricots (1/2 cup) = 2.1 mg iron
sultanas (1/2 cup) = 1.7 mg iron
milo (1 tablespoon) = 1.7 mg iron
orange (1 large) = 0.77 mg iron
baked beans (1/2 cup) = 2.2 mg iron
How does the nutrient affect the body? Iron plays an important part in keeping people healthy. Iron is vital to how cells make energy. Iron is found in blood. It is an essential part of haemoglobin, which helps carry oxygen in blood from the lungs to every body cell. It is found in many proteins and enzymes. Proteins and enzymes are needed to make new cells, hormones and substances necessary for nerve functioning. Iron helps protect from infections because it is a part of an enzyme in the immune system. It helps to convert beta-carotene to vitamin A. Vitamin A helps produce tissues that hold the body together. Iron also helps to make proteins in the body.
Information Even though we only need a small amount of iron in the body, iron-deficiency anaemia is the most common nutrient deficiency in the world. This deficiency can lead to anaemia. Symptoms include:
fatigue
irritability
shortness of breath
headache
difficulty concentrating
Women have iron-deficiency anaemia more often than men. This is because blood is lost each month during menstruation. Vegetarians are at higher risk for anaemia. Children between the ages of 1 and 4 years old and adolescents who may not get enough iron from their diets are also at risk, as are athletes.
To improve iron in the diet, the following may help:
consuming foods rich in haeme iron including lean red meat and dark poultry.
eating dark green, iron-rich vegetables with meat, poultry or seafood. The iron in the animal protein enhances absorption of the iron in the vegetables.
eating foods high in vitamin C at each meal, which enhances the body's absorption of iron, especially the harder to absorb non-haeme iron.
eating fortified grain, cereal and pasta products that have iron added to them. Check food labels, iron is required as part of the nutrition facts panel.
using iron cooking pans such as cast-iron skillets. These will add iron to the foods cooked.
avoid drinking tea when eating iron-rich foods. The tannic acid in tea reduces iron absorption by about 50%. Coffee also reduces iron absorption, but not as much.
The amount of iron needed for good health varies. The Recommended Dietary Intakes (RDIs) are:
7 mg for adult men (19 years and older).
12-16 mg for adult women ( 19 to 54 years old) .
5-7 mg for adult women (54 years and older) .
an extra 10-20 mg for pregnant women.
0.5mg for breastfed and 3mg for bottle fed infants under 6 months of age.
9 mg for infants 6-12 months old through childhood.
6-8 mg for children 1-11 years
10-13 mg for children aged 12-18
It is hard to get too much iron just from food. However, it is possible to get too much iron if vitamin and mineral supplements are used. Too much iron can be poisonous, especially for children. Vitamins with iron, including chewables made for children, should be kept out of the reach of children.
Symptoms of iron toxicity include
fatigue
anorexia (loss of appetite)
dizziness
nausea
vomiting
headache
weight loss
shortness of breath
Haemosiderosis is the name for having too much iron in the body. This comes from iron supplements or blood transfusions, not from eating too many iron-rich foods. Haemochromatosis is a genetic illness that affects how iron is absorbed and iron in these people can reach dangerous levels. At least 1 person in 300 is likely to have haemochromatosis during their lifetime. It is often undiagnosed and obvious symptoms may not appear until after the age of 30.
Author: Clare Armstrong, MS, RD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 21/09/2004 Contributors Potential conflict of interest information for reviewers available on request
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