Limited evidence suggested that iron supplementation produced a small improvement in cognitive development but had no effect on physical growth .
CONCLUSIONS : In 2 to 5 year olds , daily iron supplementation increases hemoglobin and ferritin .
There is a concerning lack of data on the effect of iron supplementation on clinical ly important outcomes including anemia , ID anemia , ID , and cognitive development .
BACKGROUND AND OBJECTIVES : Iron deficiency ( ID ) is the most common cause of anemia worldwide .
The prevalence is highest among preschool-aged children .
Iron is widely administered to children with or at risk for ID , but evidence of benefit among 2- to 5-year-old children has not been evaluated by systematic review .
We summarize the evidence for the benefit and safety of daily iron supplementation with regard to hematologic , growth , and cognitive parameters in 2 to 5 year olds .
Low dose daily iron supplementation improves iron status and appetite but not anemia, whereas quarterly anthelminthic treatment improves growth, appetite and anemia in Zanzibari preschool children.
Iron deficiency and helminth infections are two common conditions of children in developing countries . The consequences of helminth infection in young children are not well described , and the efficacy of low dose iron supplementation is not well documented in malaria-endemic setting s. A 12-mo r and omized , placebo controlled , double-blind trial of 10 mg daily iron and /or mebendazole ( 500 mg ) every 3 mo was conducted in a community-based sample of 459 Zanzibari children age 6 - 71 mo with hemoglobin > 70 g/L at baseline . The trial was design ed to examine treatment effects on growth , anemia and appetite in two age subgroups . Iron did not affect growth retardation , hemoglobin concentration or mild or moderate anemia ( hemoglobin < 110 g/L or < 90 g/L , respectively ) , but iron significantly improved serum ferritin and erythrocyte protoporphyrin .  Mebendazole significantly reduced wasting malnutrition . but only in children < 30 mo old . The adjusted odds ratios ( AORs ) for mebendazole in this age group were 0.38 ( 95 % CI : 0.16 , 0.90 ) for weight-for-height less than -1 Z-score and 0.29 ( 0.09 , 0.91 ) for small arm circumference . In children < 24 mo old , mebendazole also reduced moderate anemia ( AOR : 0.41 , 0.18 , 0.94 ) . Both iron and mebendazole improved children 's appetite , according to mothers ' report . In this study , iron 's effect on anemia was limited , likely constrained by infection , inflammation and perhaps other nutrient deficiencies . Mebendazole treatment caused unexpected and significant reductions in wasting malnutrition and anemia in very young children with light infections . We hypothesize that incident helminth infections may stimulate inflammatory immune responses in young children , with deleterious effects on protein metabolism and erythropoiesis
Limited evidence suggested that iron supplementation produced a small improvement in cognitive development but had no effect on physical growth .
CONCLUSIONS : In 2 to 5 year olds , daily iron supplementation increases hemoglobin and ferritin .
There is a concerning lack of data on the effect of iron supplementation on clinical ly important outcomes including anemia , ID anemia , ID , and cognitive development .
BACKGROUND AND OBJECTIVES : Iron deficiency ( ID ) is the most common cause of anemia worldwide .
The prevalence is highest among preschool-aged children .
Iron is widely administered to children with or at risk for ID , but evidence of benefit among 2- to 5-year-old children has not been evaluated by systematic review .
We summarize the evidence for the benefit and safety of daily iron supplementation with regard to hematologic , growth , and cognitive parameters in 2 to 5 year olds .