[Hemoglobin and nutrient concentration in middle-class adolescents. Relationship with school performance]

Concentrations of hemoglobin and serum nutrients that participate in the erythropoiesis (iron, folic acid and vitamin B12) were studied in 213 adolescents (112 male, 101 female) belonging to a medium income group that assisted at a private secondary educational institution. The purpose of the present work was to observe the hematologic and nutrient status in this group and its relationship with the academic achievement. The level of academic performance was determined using the Final mean grades (0 to 20 points scale) and the Academic Achievement index (A.A.I.) calculated as the ratio of approved courses over the total. A high prevalence of iron (16.6%) and folate (14.2%) deficiency was found in the total group with predominance in the female adolescents. It was noted a relationship between anemic men and A.A.I. (p < 0.05) and no other difference was observed between individuals with nutritional deficiency and their academic achievement. Therefore, when it was established as cut-off point 20 micrograms/L for ferritin, a good correlation was found between iron status and academic achievement index (r = 0.411, p < 0.01). The hematologic and biochemical data were correlated with academic parameters. A positive correlation was obtained between A.A.I. and hemoglobin, total iron binding capacity (TIBC) in males. When using Final mean grades, a positive correlation was shown with folic acid (males) and vitamin B12 (females). This work reveals a high incidence of iron and folate deficiency, specially in the female adolescent group. These findings may be due to a inadequate dietary intake combined with an increase of nutritional requirements and probably parasitic infestation. These factors may contribute to an impairement of the academic achievement. It will be important the assessment of iron and folate status of the adolescent for the normal and integral development of his cognitive and psychomotor functions.