Having a high prevalence in less developed countries, it is also common in industrialised countries.

Since the signs may be barely noticeable, we call it a “hidden deficiency”; and it is for the same reason that adequate treatment often begins in advanced stages of the disease.

Some nutrients are considered essential - meaning the body does not have the ability to produce them. Iron is one of them and must be obtained through the diet.

It is essential for the production of haemoglobin – a red pigment that is part of erythrocytes (red blood cells) and whose function is to capture oxygen in the lungs and transport it to all cells, in addition to carrying, on the return, some carbon dioxide so that it can be eliminated through breathing.

When iron reserves are depleted, the production of erythrocytes and haemoglobin is compromised: iron deficiency anaemia sets in.


There are many causes of iron deficiency:

  1. At certain stages of life, iron needs increase: periods of accelerated growth such as adolescence, pregnancy and breastfeeding.
  2. “Radical” diets often lead to iron deficiency, as well as changes in dietary balance (for example, in the elderly who no longer have the autonomy to prepare balanced meals). A vegetarian diet does not necessarily lead to a lack of iron, but it is necessary to take the necessary precautions to avoid it.
  3. Certain gastric diseases and the rest of the digestive tract affect absorption, particularly iron. This also includes some infections and parasites. There may be an apparently adequate intake, but the body cannot use the iron, as it does not pass from the intestinal tract into the blood.
  4. Bleeding, whether acute or chronic, necessarily leads to iron deficiency. Examples are exaggerated menstrual losses, peri- and postpartum haemorrhages, gastric ulcers, and intestinal injuries.


Initially, the manifestations are non-specific, such as fatigue, lack of concentration, tiredness with minor efforts, or susceptibility to infections. Later on, pallor, fragility of the hair and nails, angular cheilitis, dryness of skin and mucous membranes occur.

These signs and symptoms can help with the diagnosis, but it is necessary to confirm the existence of iron deficiency anaemia (excluding other causes of anaemia) through blood-specific tests: concentration of haemoglobin and ferritin (protein with the function of storing iron).

Treatment will depend on the severity of the iron deficiency: diet and supplementing with multivitamins and oral iron administration (trivalent or liposomal-sucrosomal iron complexes) or even intravenous iron.

Because food is the only source of iron, a balanced diet is the best way to prevent iron deficiency, ensuring adequate iron intake through iron-rich foods and avoiding foods or medications that compromise its absorption is crucial.

Foods rich in iron

Breast milk, meat, offal, smoked fish, shrimp, eggs, soy, beans, sweet potatoes, nuts, etc.

Foods that promote iron absorption

Fresh fruits, vegetables rich in vitamin C.


Factors that can compromise iron absorption

Food: Dairy products consumed during main meals, as well as coffee, large amounts of black or green tea and red wine

Medications: Antacids, anti-dyslipidemics, and antiplatelet agents

by Dr. Ana Montalvão
Hematologist at HPA – Alvor & Gambelas


For more information please contact Grupo HPA Saude on (+351) 282 420 400.