Iron is a trace element very present in the human body which contains between 2.5 and 4g. It enters into the constitution of hemoglobin and myoglobin, two proteins very involved in the oxygenation of the cells of the body. A lack of iron in the body usually results in anemia that can have serious consequences if left untreated.
- Trace element abundant in the human body
- In the diet, there are differentiated sources of heme iron and sources of non-heme iron
- Heme iron from meat and fish is better assimilated
- Iron deficiency anemia is very common and may result from low iron intake
- Women of childbearing age and pregnant women have increased iron requirements
Why consume foods rich in iron?
Benefits and Roles of Iron
Heme and non-heme iron
In the diet, iron is found in two different forms: heme iron and non-heme iron.
- Heme iron, which is bound to heme, is found in high quantities in meat, offal, fish and seafood. Its bioavailability is 25%. In other words, he is very well assimilated.
- Non-heme iron comes from legumes, vegetables, oleaginous plants, tofu, eggs, etc. Its bioavailability is only 5 to 10%. We assimilate it less well than iron from animal products.
Ideally, and to avoid iron deficiency, it would be necessary to have a diet combining both types of iron.
Oxygenation of cells
Iron enters into the constitution of hemoglobin. Hemoglobin is found in red blood cells responsible for oxygenating the various organs and tissues of the human body.
It also forms myoglobin, a form of oxygen reserve in the muscle. Iron is very related to oxygen in the body. Therefore, among the common symptoms of anemia, there is shortness of breath or pallor.
Iron is involved in many metabolic reactions, it is essential for the proper functioning of the body. It allows the synthesis of DNA and some neurotransmitters such as adrenaline or norepinephrine.
20 foods containing iron
|Braised pork liver||100 g||18 mg|
|Lamb or chicken liver, braised or sauteed||100 g||8-13 mg|
|Braised lamb kidneys||100 g||12 mg|
|Cooked soy beans||250 ml (1 cup)||9 mg|
|Oysters from the Pacific Ocean raw or steamed||100 g (2-4 medium)||5-9 mg|
|White beans and cooked lentils||250 ml (1 cup)||5-8 mg|
|Poultry offal stewed||100 g||6-8 mg|
|Beef liver braised or fried||100 g||6-7mg|
|Boudin cooked||100 g||6 mg|
|Braised or sauteed veal liver||100 g||5-6 mg|
|Red beans, chickpeas or lima beans, cooked||250 ml (1 cup)||3-6 mg|
|Tofu||100 g||5 mg|
|Horse||100 g||5 mg|
|Dehydrated Pumpkin and Pumpkin Seeds||1/4 cup (60 mL)||5 mg|
|Breakfast cereals||30 g||4 mg|
|Beef, roasted palette, braised||100 g||4 mg|
|Crushed tomatoes, canned||250 ml (1 cup)||3 mg|
|Boiled spinach||125 ml (1/2 cup)||3 mg|
|Shrimps, raw or cooked||100 g||2-3 mg|
|Canned clams||100 g||2.8 mg|
How to use iron?
Use of iron
|Recommended Dietary Allowance (ANC)|
|Babies 0-6 months||0.27 mg *|
|Babies 7-12 months||11 mg|
|Babies 1-3 years old||7 mg|
|Children 4-8 years old||10 mg|
|Boys 9-13 years old||9 mg|
|Girls 9-13 years old||9 mg|
|Boys 14-18 years old||11 mg|
|Girls 14-18 years old||11 to 16 mg|
|Men 19-50 years old||11 mg|
|Women 19-50 years old||11 to 16 mg|
|Men 50 and over||11 mg|
|Women 50 and over||11 mg|
|Pregnant women||30 mg|
|Nursing women||11 mg|
* Sufficient contributions
Food supplements based on iron
There are many food supplements containing iron. Often indicated to prevent or treat anemia, they can also be used after digestive surgery, at the top athlete, pregnant women or people on a vegetarian or vegan diet. The dosage varies according to the problem and the context, the supplementation must be done under medical supervision.
Undesirable effects of iron
What happens when there is too much iron in the blood?
Excess iron in the blood can be pathological (hemochromatosis) or result in too much intake. Too much, iron has a pro-oxidative effect, that is, it promotes oxidative stress and premature aging of cells. It could be responsible, in the long run, for an increased risk of digestive cancers. Hemochromatosis can be responsible for hepatomegaly (enlargement of the liver) that can progress to cirrhosis and liver cancer.
Consequences of a lack of iron
Iron deficiency is much more common than excess iron. It causes anemia that quickly translates into a drop in certain blood levels. If anemia is related to a lack of iron, it is called iron deficiency anemia. This type of anemia is very common, especially in women who have increased needs for menstrual bleeding. This is also the case in some other situations at risk of malabsorption (chronic bowel disease, gastric surgery, etc.). Anemia is manifested by various symptoms: pallor, fatigue, shortness of breath, muscle weakness, hair loss, chills, dull skin, etc.
Interactions with other nutrients
Vitamin C increases iron absorption by the body. The presence of heme iron (from meat) in a meal increases the uptake of non-heme iron (from plants, eggs and dairy products) present in the same meal.
In contrast, tannins (mainly tea), phytates, fiber, calcium, magnesium and zinc reduce its assimilation. It is, for example, not recommended to consume tea around the meal to avoid the absorption of iron. In general, a varied and balanced diet can provide enough iron despite these interactions.
The iron symbol is Fe, its atomic number is 26. The atomic mass of iron is 55.845 u, its density is 7.874 g.cm-3. Iron is a gray-silver transition metal.
It is often found in combination with carbon to form steels to use the material in larger areas.
Although very old, the use of iron in metallurgy remained secret until the twelfth century BC Since then, the use of iron will become massive and we even speak of “Iron Age” to designate the time. Since then, iron has been used in various fields (metallurgy, architecture, etc.) and its roles in the body have been studied by science. For example, currently the link between excess iron, oxidation and digestive cancers is the subject of in-depth scientific studies.