Iron - NZ Nutrition Foundation

We need iron to produce haemoglobin in our blood, which carries oxygen around our bodies. Our immune system also needs iron to work well.

How much iron do we need?

	Age (years)	RDI* Iron (mg/day)
Infants	7-12 months	11
Children	1-3	9
	4-8	10
	9-13	8
Girls	14-18	15
Boys	14-18	11
Men	19-70+	8
Women	19-50	18
	Over 50	8
Pregnant women	14-50	27
Breastfeeding women	14-18	10
	19-50	9

Source: Iron | NRV

Who needs more and why?

Babies, children and teenagers because they are growing rapidly
People who have periods, due to loss of blood each month
Pregnant women who need enough iron for themselves and their growing baby. This is particularly true towards the end of pregnancy when the baby grows rapidly.
Athletes, particularly endurance runners

Which foods contain iron?

There are two types of iron in food: haem iron (absorbed very well) and non-haem iron (not absorbed very well). Meat, poultry, and seafood contain both haem iron and non-haem iron. Plant foods, such as vegetables, cereals, beans, and lentils, contain only non-haem iron so the iron in these foods is not absorbed as well by the body.

The best sources of iron are:

beef and lamb (the redder the meat, the more iron there is in it)
shellfish e.g. mussels, oysters
chicken, fish

Other foods with iron are:

grains: porridge, oatmeal, iron-fortified breakfast cereals (eg, Weetbix), and wholegrain bread
vegetables: greens (spinach, silverbeet, lettuce), beans and peas, pumpkin and sweet potatoes
eggs
chickpeas, beans, lentils
some nuts and seeds

Haem iron content of foods

Foods containing haem iron	Iron (mg)
1 grilled lean beef fillet steak (173g)	5.8
½ cup green mussels, marinated	7.5
2 grilled lean lamb leg steaks (116g)	4
1 slice fried lamb liver	4
90g can salmon	2.1
1 grilled chicken breast (107g)	2
1 grilled lean pork loin chops (74g)	1.2
1 baked tarakihi fillet	0.8

Non-Haem Iron content of foods

Foods containing non-haem iron	Iron (mg)
100g tofu	5.4
1 cup porridge	1.3
1 Wheat biscuit	1.5
½ cup cooked red kidney beans	2
½ cup cooked boiled lentils	1.2
½ cup fruity muesli	1.9
½ cup cooked chickpeas	1.6
1 cup boiled broccoli	0.9
½ cup baked beans	1.6
10 dates	1.3
1 cup boiled spinach	2.5
1 boiled egg	0.9
1 slice multigrain bread	0.7

How can I get enough iron?

Lean red meat is the best source of easily-absorbed haem iron, so try to include it 3-4 times per week. Other meats (chicken, poultry, pork) and fish are also good sources of easy to absorb iron, so eat a variety of these to increase your iron intake.
To increase the absorption of non-haem iron try to have vitamin C-rich foods – such as kiwifruit, citrus fruits, orange, and capsicums – at the same time. For example, topping with your breakfast cereal with kiwifruit will increase the iron absorbed from the cereal.
Combining haem foods with non-haem foods also increases the absorption of iron. For example, adding lean meat to a salad sandwich increases the amount of iron absorbed from the bread and salad.
If you don’t eat meat and seafood, try to include foods that are rich in non-haem iron such as tofu, iron-fortified breakfast cereals, and cooked beans and lentils every day.
Tea reduces the amount of iron absorbed by the body. Drink tea between meals, or wait at least ½ -1 hour after eating.

Iron and blood levels

Low levels of blood haemoglobin are relatively common, particularly among those needing the most iron. Too little iron in the blood can lead to paleness, tiredness, and lethargy, making it harder to concentrate, and affecting our performance at school or work. Resistance to illness, such as infections, coughs, and colds, is also weaker.

Low blood levels can be caused by:

not eating enough iron-rich foods
an increased need for iron, e.g. during pregnancy
iron lost in the gut through conditions such as peptic ulcers, tumours, or ulcerative colitis.

Having too much iron in the blood is also possible, but much less common. It can be caused by taking iron supplements when not needed, a high alcohol intake, hepatitis, or haemochromatosis (a condition where a person’s body absorbs too much iron).

If you are concerned about your blood levels of iron e.g. have heavy periods, are tired, weak, lightheaded, or look pale, talk to your doctor about having a blood test. Iron supplements should only be taken under medical supervision, as unsupervised use of iron supplements can reduce the absorption of other essential nutrients, such as zinc and calcium.

More info

Health Navigator: Iron

References

National Health and Medical Research Council (Australia) and Ministry of Health (New Zealand) (2014) Nutrient Reference Values for Australia and New Zealand: Iron.

Last reviewed: 25/07/2022