M. Ruz et al., A 14-MO ZINC-SUPPLEMENTATION TRIAL IN APPARENTLY HEALTHY CHILEAN PRESCHOOL-CHILDREN, The American journal of clinical nutrition, 66(6), 1997, pp. 1406-1413
Apparently healthy preschool children (46 boys, 52 girls) aged 27-50 m
o from low socioeconomic conditions who attended daycare centers in Sa
ntiago participated in a 14-mo long double-blind zinc supplementation
trial. Unlike most previous studies, no additional inclusion criteria
such as short stature or slow growth rate were considered. Subjects we
re pair matched according to sex and age and randomly assigned to two
experimental groups: the supplemented group, which received 10 mg Zn/d
, and the placebo group. Selected anthropometric, clinical, dietary, b
iochemical, and functional indexes were determined at the beginning of
the study and after 6 and 14 mo of intervention. Actual dietary zinc
intake was 66% of the recommended dietary allowance. Height gain after
14 mo was on average 0.5 cm higher in the supplemented group (P = 0.1
0). The response, however, was different between sexes. Boys from the
supplemented group gained 0.9 cm more than those in the placebo group
(P = 0.045). No effect was seen in girls. Although no significant diff
erences were observed in the rest of the variables studied, trends (0.
05 < P < 0.10) in the supplemented group compared with the placebo gro
up for increased midarm muscle area in boys, improved response to tube
rculin, and reduced rates of parasite reinfestation were noted. We con
clude that in preschool children of low socioeconomic status, zinc is
a limiting factor in the expression of growth potential.