I will address an important topic that still causes major morbidity and mortality around the world, especially in low income populations and children.
2. Iron-deficient erythropoiesis: after iron stores are exhausted, lack of iron limits the production of hemoglobin and other metabolically active compounds that require iron as a constituent or cofactor.
Globally, the most common cause of anemia is iron deficiency. Other possible causes are acute or chronic infections, parasitic diseases, heavy menstruation, hemoglobinopathy, colon cancer, and vitamin A/B12 or folate deficiency, among others.
Various epidemiological studies have shown that iron deficiency anemia is still one of the most prevalent nutritional deficiencies. Iron deficiency is present in up to 30% of women, and 70% of pregnant women. A recent cross-sectional study investigated the prevalence and possible risk factors for iron deficiency anemia on aboriginal schoolchildren living in remote areas in Malaysia. Overall, 48.5% of children were anemic. Low levels of mothers' education and low household income were identified as risk factors; severe trichuriasis was also found to be associated (Al-Mekhlafi 1046).
If this deficiency is present during the first two years of life, a functional disturbance is highly probable, given that the developing brain experiences structural and biochemical changes; a few weeks after birth, synapses formation takes place and the nervous system starts its shaping, being a critical time with high vulnerability. Moreover, anemia may affects cognitive function at all stages of life.
The immune system depends of multiple oxidation processes; another possible outcome in people with anemia is a state of immunodeficiency. Pregnant women with anemia may experience complications and increased mortality rates.
Finally, anemia in adults may have economic consequences because it provides low physical and work performances, increasing disability and work incapacities.
It is important to define the severity and etiology of anemia, in order to start an adequate therapeutic approach. Clinical symptoms and physical examinations have low sensitivity and specificity. According to WHO, Hb concentration is the most reliable indicator of anemia at the population level, and measuring it is relatively easy and inexpensive. However, the etiology of anemia should be interpreted with caution if the only indicator used is Hb concentration. A complete blood count gives important information that can guide into the possible cause. Other important tests are serum ferritin, serum iron, transferrin, and transferrin saturation.
Anemia is not a specialized disease.