Effect of iron supplementation on mental and motor development in children: systematic review of randomised controlled trials.
OBJECTIVE
To evaluate the effect of iron supplementation on mental and motor development in children through a systematic review of randomised controlled trials (RCTs).


METHODS
Electronic databases, personal files, hand search of reviews, bibliographies of books, abstracts and proceedings of international conferences.


METHODS
RCTs with interventions that included oral or parenteral iron supplementation, fortified formula milk or cereals were evaluated. The outcomes studied were mental and motor development scores and various individual development tests employed, including Bayley mental and psychomotor development indices and intelligence quotient.


RESULTS
The pooled estimate (random effects model) of mental development score standardised mean difference (SMD) was 0.30 (95% confidence interval (CI) 0.15 to 0.46, P<0.001; P<0.001 for heterogeneity). Initial anaemia and iron-deficiency anaemia were significant explanatory variables for heterogeneity. The pooled estimate of Bayley Mental Development Index (weighted mean difference) in younger children (<27 months old) was 0.95 (95% CI -0.56 to 2.46, P=0.22; P=0.016 for heterogeneity). For intelligence quotient scores (> or =8 years age), the pooled SMD was 0.41 (95% CI 0.20 to 0.62, P<0.001; P=0.07 for heterogeneity). There was no effect of iron supplementation on motor development score (SMD 0.09, 95% CI -0.08 to 0.26, P=0.28; P=0.028 for heterogeneity).


CONCLUSIONS
Iron supplementation improves mental development score modestly. This effect is particularly apparent for intelligence tests above 7 years of age and in initially anaemic or iron-deficient anaemic subjects. There is no convincing evidence that iron treatment has an effect on mental development in children below 27 months of age or on motor development.
Sachdev
Hps
H
SL Jain Hospital, New Delhi 110 052, India. hpssachdev@hotmail.com
Gera
Tarun
T
Nestel
Penelope
P
D000293:Adolescent; D018798:Anemia, Iron-Deficiency / Q000150:complications / Q000188:drug therapy*; D002648:Child; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D003071:Cognition / Q000187:drug effects*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007501:Iron / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D011597:Psychomotor Performance / Q000187:drug effects*; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors; D016896:Treatment Outcome
D007501:Iron