Iron deficiency Anemia

Normal RBC

Maturation stages

Morphological characteristics

Hemoglobin synthesis involves 2 biosynthetic pathways

Red cell turnover

Control of erythropoiesis

Main function of RBC's

Transport of oxygen is influenced by pH, 2-3-DPG level and valence of iron.

Steps in evaluation of a patient with anemia.

  1. Distinction between hypo and hyperproliferative anemia

  2. Use of red cell size to further narrow down the possibilities

  3. Review the blood smear

Reticulocyte count helps to categorize the anemia into hypo-or hyper-proliferative type.




Reticulocyte count

There are three ways to express retic response

  1. Retic count

  2. Corrected retic count

  3. Absolute retic count

Retic count: Reticulocytes are counted as the number of NMB-reactive cells per 1,000 red cells and expressed as percent reticulocytes (absolute number per 100 red cells).

Her  reticulocyte count  is 2.5%. 

Corrected reticulocyte count  = %reticulocyte X (Patient's Hct/Expected normal Hct of 40)

Our patient's Corrected reticulocyte count is 2.5 x 23 / 40. It is 1.2%. 

Less than 2% =  hypoproliferative type. This means that her anemia is due to underproduction of red cells by the bone marrow. 

Absolute Reticulocyte count


Differential for microcytic hypo chromic anemia.

Iron deficiency 

Microcytic anemia

To confirm iron deficiency 

  1. Serum Iron

  2. Total Iron-binding capacity

  3. Saturation

  4. Ferritin

Serum Iron measures Transferrin-associated ferric ion  Normal Range: 12.7 to 35.9 µmol/L (60 to 180 µg/dl) Decreased serum iron levels may precede changes in red cell morphology or in red cell indices All transport iron in the plasma is bound in the ferric form to the specific iron-binding protein, transferrin. Serum iron refers to this transferrin-bound iron. Serum iron concentration is increased in the sideroblastic anemia's and in some cases of thalassemia.

Total Iron-binding capacity  Normal Range: 45.2 to 77.7 µmol/L (250 to 410 µg/dl) TIBC, the concentration iron necessary to saturate the iron-binding sites of transferrin, is a measure of transferrin concentration.

Transferrin Normal range170-370 mg/dl 

Saturation of transferrin is calculated by the following formula % Transferrin Saturation = Serum Iron (mol/L) X 100.: Normal mean transferrin saturation is approximately 30%. Normal range 20% to 50%

A normal plasma iron level and iron-binding capacity do not rule out the diagnosis of iron deficiency when the hemoglobin level of the blood is above 90 g/L (9 g/dl) (females) and 110 g/L (11g/dl) (males). 


Anemia of chronic disorder

Tissues /cells require Iron for normal development

Normal resource for iron in diet

Vitamins and many food items (Cereal) are fortified with iron.

Daily requirement of iron for a normal adult

Common causes of iron deficiency anemia. 

Most important cause is chronic blood loss.

Menstruating women:

Males and Post menopausal women

GI tract blood loss

Nutritional deficiency (Not in USA)

Malabsorption (Sprue, gatrectomy)

Rare causes

Clinical sequelae to iron deficiency anemia

Therapeutic strategy for treatment of iron deficiency anemia

Therapeutic response

Iron absorption

Problems associated with iron therapy

Role for Blood transfusion

You do not need blood transfusions even in severe chronically anemic patients. Patients adapt to chronic anemia extremely well and Iron replacement therapy can correct the problem gradually. You can do harm from transfusion  by throwing them into heart failure, for already they have a high output state.