Efecto de la complementación con zinc en la velocidad de crecimiento en niños preescolares

Introduction: In Colombia the decrease of malnutrition documented by surveys is associated with the decrease in infectious diseases and increase consumption of fats and sugar representing half caloric intake and increasing the risk of other nutrients deficiencies. The permanence of low stature in populations satisfying macronutrient requirements, suggest that there are other limiting factors in the diet. Objective: To evaluate possible deficit of Zinc or other nutrients in growth velocity a double blind study was done in Cali, Colombia. Methods: From 9 low and middle low socio-economic level day care centres 270 preschool healthy children with adequate macronutrient intake were selected and followed monthly for 17 months. At month 8^th they were randomly divided in two groups and received a daily mineral and vitamin supplement with zinc (12 mg) and without zinc for the next 9 months. Dietary intake was measured and all of the children with parasites were treated initially. Anthropometrics were measured every month during the two periods. Zinc in nails, hair and plasma at the first and last visit. Results: The proportion of children with Z height age below -2SD was less than 2% in the first visit. Mean height increased after the supplement regardless of zinc but was higher in those receiving it. There were differences before and after and among children receiving or not Zn when the variables were adjusted by age and/or reference. Significant differences were found in variance and proportions. The probability of increase height Z or velocity with zinc is 1.8(CI95% 1.02-3.12) and 1.09 (CI 95% 0.954-1.251). There was not difference in Zn concentration in plasma, hair or nails. Conclusion: The deficience of other micronutrients besides zinc, that limit the growth could explain the improvement of velocity for the two groups. Probably in poorest children, the response would be high.