Normal Haematological Values in the Central American Population

S ummary . A total of 6787 subjects were studied, representative of the Central American populations but without clinical evidence of haematological disease. Out of this sample, 452 individuals fulfilled the following conditions: they were hook‐worm free, with values of serum iron > 50 μg/100 ml; saturation of transferrin > 20%; serum folates ( L. casei ) > 5 ng/ml; and serum vitamin B 12 ( E. gracilis ) > 150 Pg/ml. These individuals were considered adequately nourished from the erythropoietic point of view, and they constituted the ‘normal’ sample from which values for haemoglobin, packed cell volume, red blood cell count, and red blood cell indices were calculated. These subjects were grouped by age and sex, and according to the altitude above sea level of their place of residence (0‐750 and 751–1500 m). Results from this highly selected sample indicate that haematological values are equal or higher to those reported for ‘normal’ individuals from well‐nourished, non‐tropical populations. To our knowledge, this is the only study where norms have been derived from a population sample with well‐documented ‘normal’ serum values for iron, % saturation of transferrin, folate and vitamin B 12 . From these data, haematological values below which the risk for an individual having a subnormal haematological state increase, are derived and discussed.