Essential for the transport of oxygen and the formation of red blood cells in the blood, iron is a constituent of hemoglobin. When and how to do a dosage? A cure? What to do in case of deficiency? Overdose? What are the consequences? The point with Dr. Eric Atlani, the general practitioner.

Definition: What is iron?

"Iron is a trace element that circulates in plasma or can be stored in organs," says Dr. Eric Atlani, a general practitioner in Cannes. It is necessary to distinguish in the average patient serum iron, which refers to the level of iron, which is not fixed to red blood cells, but which is circulating in the plasma, and ferritin, a protein, allowing the storage of iron, and which corresponds to the iron reserves of the patient' Sometimes, when analyzing iron in a patient, "serum iron may be high, but the storage (iron reserves) is a bit low," he says.

► Heme iron is 'ferrous' iron from animal foods such as meat, poultry, offal, and fish. It is associated with hemoglobin and myoglobin, and represents about 70% of the iron present in the body;

► Non-heme iron is present in plants: cereals, fruits, vegetables, eggs, spirulina. Only 1 to 10% of this iron is absorbed by the body.

What is its role for the organization?

The human body does not naturally make iron.

Iron is a constituent of hemoglobin. It is used to transport oxygen through red blood cells in all the so-called 'noble' organs (brain, kidneys, heart, muscles ...). Its role is therefore essential. "You have to know that the human body does not naturally make iron. Its rate in the body, therefore, depends on the intake and use of iron. That's why there can be a lot of iron deficiencies," he says.

What are the daily needs?

"In general, iron requirements in men and women are between 10 and 20 mg of daily intake in men and women, and above 20 mg in pregnant women, women who have and in regular athletes," observes Dr. Atlani. In children, iron requirements are between 6 and 10 mg per day. In 2016, the nutritional references of the adult population were updated* and are estimated at exactly 11 mg/d for:

Man;
Women with low or normal menstrual losses (80% of the premenopausal female population);
Postmenopausal women and 16 mg/d for premenopausal women with high menstrual discharge.

How to dose iron?

"The determination of serum iron (circulating in plasma) is done through a blood test," says Dr. Atlani. It is also possible to perform a liver biopsy to have a notion of the iron level in the liver - or to perform a liver MRI. In everyday life, however, a blood test is the most common. 'The last two examinations are prescribed when there is a suspicion of hemochromatosis (a genetic disease characterized by intestinal iron hyperabsorption).'

When to do an iron dosage?

"We often start with a simple ferritin dosage to look at the iron reserves. If the reserves are low, as well as the hemoglobin too, there is a suspicion of iron deficiency anemia (decrease in the number of red blood cells in the blood or their hemoglobin content)', describes Dr. Atlani, In this case, we realize most of the time:

► A serum iron assay;

► A transferrin assay (to know the saturation coefficient, which gives a good idea of blood transport).

"I prefer to ask for a ferritin dosage in all my standard checkups. With diets such as vegetarianism or veganism, increasingly adopted by a part of the population, there may be iron deficiencies that must be monitored," observes our interlocutor.

Iron deficiency: consequences, what to do?

"Since iron is a constituent of hemoglobin, if iron is lacking, it cannot efficiently carry oxygen," notes the doctor. Iron deficiency can manifest as the following symptoms:

Fatigue (the first sign of lack of iron);
Ideatory slowness (feeling of losing intellectual abilities, lack of words, concentration ...);
Dyspnea (shortness of breath);
Pallor especially in iron deficiency anemia;
Orthostatic hypotension (when moving from sitting or lying down to standing);
Decreased libido in some patients;
More fragile dander (hair loss especially in women, nails that will break);
Pruritus: people scratch because they have dry skin, this is one of the consequences of an iron deficiency;
Regular bleeding is more abundant (hemorrhoids, menstruation ...) especially in the context of iron anemia.

Iron overload: consequences, what to do?

When there is an iron overload, it means that iron is too abundant in the blood. "The main cause sought is hemochromatosis - the main organ affected by this genetic disease being the liver, a liver biopsy or liver MRI is performed. It may be possible to spot iron overload through an abnormality in liver function, but otherwise, there are no particular symptoms as for an iron deficiency. The only treatments for iron overload in a carrier of the hemochromatosis gene consist of monitoring as well as bleeding. "Often, iron overload is a fortuitous discovery, or there is a family history of hemochromatosis that motivated ferritin testing," he adds.

When to do an iron cure?

An iron cure is performed when iron deficiency is diagnosed. Taking iron-based medications lasts between two and three months. "It takes at least a month for everything to fall into place, and well two months to do the iron refills," says Dr. Atlani. Note that iron-based drugs color the stool, so do not worry if you notice this phenomenon.

What foods are rich in iron?

Red meat, especially cooked black pudding, lamb liver...;
Poultry liver;
Fish and seafood;
Cereals (dry lentils, wheat germ, cooked or dried white beans...);
Spirulina;
Spices (rosemary, sage, curry ...).

'Some substances, on the contrary, reduce the transit of iron: we can mention coffee for example, or certain teas (green tea makes iron lose, black tea decreases its absorption). You should know that vitamin C improves iron absorption. It is therefore advisable to eat foods rich in vitamin C, such as blackcurrant, cabbage, parsley, lemon, pepper, broccoli ...', explains our interlocutor.

Iron during pregnancy

During pregnancy, the blood volume increases. The pregnant woman, therefore, needs more iron for her organs to function properly. "Serum iron consumption is higher in pregnant women," says Dr. Atlani. The slightest iron deficiency can aggravate phenomena of orthostatic hypotension, shortness of breath, dizziness, fatigue, etc.'. In case of iron deficiency during pregnancy, iron supplementation is prescribed by the doctor, often from the fifth month.