Anemia is a disorder of oxygen transport and delivery due to qualitative and / or quantitative changes in circulating red blood cells. It is a widespread disease, with the highest incidence of iron deficiency anemia.
Risk periods for the development of iron deficiency anemia are early childhood, puberty and pregnancy with lactation. The causes of iron deficiency anemia can be different - low iron intake with food, chronic blood loss  (most often from the gastrointestinal tract and female genitals), gastric and intestinal diseases (atrophic gastritis, resections, enterocolitis, parasitosis), chronic infections, carcinomas and others.
The main symptoms in patients with anemia are often a feeling of fatigue ; low tolerance to physical activity; rapid pulse, even at rest; the skin and mucous membranes are pale, but with darker skin pigmentation this symptom may go unnoticed. With a longer duration of the disease, changes in concentration and more difficult assimilation of new information are possible.
Only a small part (about 10-15%) of the iron ingested with food is absorbed by the body. In foods rich in heme iron (associated with a protein carrier), the absorption of iron from food can reach up to 20%. Rich in heme iron are meat products - meat and animal offal (spleen, liver, kidneys), some fish and seafood. While foods containing non- heme iron are cereals, legumes, nuts, most vegetables and more. Increased absorption of non-heme iron is observed with the simultaneous intake of foods containing it with foods rich in vitamin C.
Hydrochloric acid in the stomach has a role in converting ferric iron into divalent, which is also easier to digest. The enzyme pepsin is also released in the stomach, whose role is to release iron from its protein transporter, allowing it to be further absorbed in the small intestine. In patients suffering from reduced secretion of hydrochloric acid from the gastric mucosa or taking antacids, there is a significant decrease in iron absorption.
Foods rich in fiber, phytates and oxalates can significantly reduce the absorption of iron with food. These are mainly cereals. The content of phosphates in dairy products also leads to reduced absorption of iron. Rich in oxalates are green leafy vegetables - lettuce, spinach and others.
The body's daily needs for iron are also related to its physiological losses through the kidneys, intestinal tract, as well as smaller amounts through the bile and skin. The need for iron is increased during pregnancy, lactation (breastfeeding), menstruation , as well as during frequent and prolonged physical activity (in athletes).
Iron requirements are high in early childhood, with children from 6 months to 4-5 years of age being particularly sensitive. Breast milk is relatively poor in iron, but with very high absorption (up to 40-50%). There is a risk of iron deficiency in premature babies, as well as newborns who have had perinatal blood loss.
In men, the average amount needed by the body is 1 mg per day of absorbed iron, while in women of childbearing age the requirements are slightly higher - 1.5 mg of absorbed iron. After menopause, the need for iron in men and women equalizes due to the cessation of monthly menstruation.
Old age is characterized by indigestion and atrophic changes in the gastric mucosa. This is the reason why the intake of foods rich in iron is increased so that its absorption is kept within normal limits.
Iron deficiency anemia continues to be a problem for both developing and developed countries . It is important to timely diagnose and change the diet, and if necessary, drug therapy.