Daily dose

The recommended daily dose is

• 10 mg for men
• 15 mg for women (the need increases after menstruation or during pregnancy)

Properties

Indications

• Anaemia
• Pregnancy (as iron requirements increase)
• Premenstrual tension
• Tiredness

Requirement

Iron deficiency is much more common than iron overload.

It causes anaemia, which quickly leads to a drop in certain blood counts.

If the anaemia is due to a lack of iron, it is called iron deficiency anaemia.

This type of anaemia is very common, especially in women who have increased needs due to menstrual losses.

This is also the case in some other situations where there is a risk of malabsorption (chronic bowel disease, gastric surgery, etc.).

Anaemia causes various symptoms: paleness, fatigue, shortness of breath, muscle weakness, hair loss, chills, dull skin, thrush, etc.

Excess

Excess iron in the blood can be pathological (haemochromatosis) or the result of excessive intake.

Excess iron has a pro-oxidant effect, i.e. it promotes oxidative stress and premature ageing of cells.

In the long term, it may be responsible for an increased risk of cancer of the digestive tract.

Haemochromatosis, on the other hand, can be responsible for hepatomegaly (enlargement of the liver), which can develop into cirrhosis and then liver cancer.

Observations

• Iron preparations (supplements) can cause side effects such as constipation, diarrhoea or stomach pain.
• Although iron is best absorbed when you are fasting, it is advisable to take iron supplements with meals if you are experiencing side effects.
• Iron in the form of Fe2+ is better absorbed than Fe3+ (also known as ferric iron).
• Anaemia problems may be caused by a diet that is too low in iron or by a problem in absorbing the iron.
• It is important not to exceed the maximum daily dose of iron to avoid side effects that could be dangerous to your health.

Blood test for iron

It is interesting to know that it is easy to measure your blood iron levels with a simple blood test.

Your doctor can check the amount of iron in your body (it actually measures ferritin, a protein that stores iron, and sometimes another protein, transferrin, which transports iron around the body).

More information

Haem iron: iron of animal origin (e.g. meat). This iron is better absorbed by the body than non-haem iron, to the tune of 25% or more.

Non-haem iron: iron of vegetable origin (e.g. green leafy vegetables). This iron is not absorbed as well as haem iron; absorption is estimated at less than 5%.

Interactions with other nutrients

Vitamin C increases the body's absorption of iron.

The presence of haem iron (from meat) in a meal increases the absorption of non-haem iron (from plants, eggs and dairy products) in the same meal.

On the other hand, tannins (mainly from tea), phytates, fibre, calcium, magnesium and zinc reduce their absorption.

For example, it is not recommended to drink tea close to a meal so as not to interfere with iron absorption.

In general, despite these interactions, a varied and balanced diet provides sufficient iron.

Chemical properties

The symbol for iron is Fe and its atomic number is 26.

The atomic weight of iron is 55.845 u and its density is 7.874 g.cm-3.

Iron is a silver-grey transition metal.

It is often combined with carbon to form steels, allowing the material to be used over larger areas.

Iron food supplements

There are many dietary supplements that contain iron.

They are often used to prevent or treat anaemia, but may also be used after digestive surgery, by competitive athletes, by pregnant women, or by people on vegetarian or vegan diets.

Dosages vary according to the problem and context, and supplementation should be done under medical supervision.

Nutrients that contain iron

20 foods containing iron

Food - Portions - mg

• Pork liver, fried - 100g = 18mg
• Lamb or chicken liver, braised or fried - 100g = 8-13mg
• Braised lamb kidney - 100g = 12mg
• Cooked soya beans - 250ml (1 cup) = 9mg
• Raw or steamed Pacific oysters - 100g (2-4 medium) = 5-9mg
• Cooked white beans and lentils - 250ml (1 cup) = 5-8mg
• Braised poultry giblets - 100g = 6-8mg
• Braised beef liver - 100g = 6-7mg
• Boiled black pudding - 100g = 6mg
• Braised or fried veal liver - 100g = 5-6mg
• Beans, chickpeas or lima beans, cooked - 250ml (1 cup) = 3-6mg
• Tofu - 100g = 5mg
• Horse mackerel - 100g = 5mg
• Pumpkin seeds - 60ml (1/4 cup) = 5mg
• Breakfast cereals - 30g = 4mg
• Roast beef, fried - 100g = 4mg
• Tinned crushed tomatoes - 250ml (1 cup) = 3mg
• Cooked spinach - 125ml (1/2 cup) = 3mg
• Prawns, raw or cooked - 100g = 2-3mg
• Canned clams - 100g = 2.8mg
• Spirulina