Significant heterogeneity was evident , and its predictors included greater weight-for-age in supplemented children in malaria hyperendemic regions and greater weight-for-height for children above 5 years of age , but a negative effect on linear growth in developed countries and with supplementation for 6 months or longer .
This review did not document a positive effect of iron supplementation on the physical growth of children .
OBJECTIVE To evaluate the effect of iron supplementation on  physical growth in children through a systematic review of r and omised controlled trials ( RCTs ) .
Zinc supplementation reduced morbidity, but neither zinc nor iron supplementation affected growth or body composition of Mexican preschoolers.
In rural Mexico and in many developing countries micronutrient deficiencies , growth stunting , and morbidity from infectious diseases are highly prevalent in young children . We assessed the extent to which growth stunting could be reversed and the number of infectious disease episodes reduced by zinc and /or iron supplementation . In a double-blind , r and omized community trial 219 Mexican preschoolers were supplemented with either 20 mg Zn as zinc methionine , 20 mg Fe as ferrous sulfate , 20 mg Zn + 20 mg Fe , or a placebo . After 12 mo , plasma zinc increased significantly in the two zinc-treated groups , and plasma ferritin was significantly higher in the two iron-treated groups . There was no effect of treatments on growth velocity or body composition . Children in both zinc-supplemented groups had fewer episodes of disease ( zinc alone , 3.9 + /- 0.3 ; zinc+iron , 3.7 + /- 0.4 ; placebo , 4.6 + /- 0.5 ; P < 0.03 ) , including diarrhea ( zinc alone , 0.7 + /- 0.1 ; zinc+iron , 0.8 + /- 0.1 ; placebo , 1.1 + /- 0.2 ; P < 0.01 ) . Zinc and zinc+iron supplements reduced morbidity but had no effect on growth or body composition
Significant heterogeneity was evident , and its predictors included greater weight-for-age in supplemented children in malaria hyperendemic regions and greater weight-for-height for children above 5 years of age , but a negative effect on linear growth in developed countries and with supplementation for 6 months or longer .
This review did not document a positive effect of iron supplementation on the physical growth of children .
OBJECTIVE To evaluate the effect of iron supplementation on  physical growth in children through a systematic review of r and omised controlled trials ( RCTs ) .