The study of the hematologic responses during exposure to extreme altitude has been of great interest from physiology. However, most people do not live, travel or reside at extreme altitude. In Colombia 70% of the population resides in intermediate altitudes between 1500 m and 3000 m and there are no normal values for indicators of erythropoiesis and iron status in these altitudes in Colombia and in the world. Obtaining these values allows the first approach to normal values of the indicators of the erythropoiesis and the state of the iron at intermediate altitudes in Colombian population and it will change the decision making on exercise prescription, cardiorespiratory therapy, and detection of doping in athletes, being more suited to the resident population living in these altitudes. Purpose: The present research aimed to determine the behavior of some indicators of erythropoiesis and iron status at different altitudes in Colombian university population. To determine the behavior of erythropoietin, reticulocytes, hemoglobin concentration, hematocrit, ferritin and soluble transferrin receptor in population between 18 and 30 years old, residents at 1728 m, 1923 m, 2180 m and 2600 m. To determine whether there are gender differences in these variables. To determine whether there is a threshold for erythropoiesis.