COMMENTARY |
Does Iron-Deficiency Anemia Affect Child Development?
Center for International Child Health, Institute of Child Health, University College London, London, United Kingdom WC1N IEH
Abbreviations: IDA, iron deficiency anemia • RCTs, randomized • controlled trials
The global prevalence of iron-deficiency anemia (IDA) is extremely high. The possibility that IDA affects children’s development is therefore a serious public health problem and has implications not only for individuals’ development but also for national development in countries with high prevalence. Although infants with mild-to-moderate IDA have poor development both concurrently and in later childhood,1,2 a causal link is not well-established.3
A major problem is that IDA is associated with many socioeconomic disadvantages1,2 that are likely to have independent effects on children’s development. Therefore randomized, controlled trials (RCTs) of iron supplementation are essential to allow causal inferences. Trials of treating IDA indicate whether the effects are remediable whereas preventive trials provide the strongest evidence of causality.
Surprisingly few RCTs of iron supplementation have been conducted in infants. Previous treatment trials have often lacked randomized designs and failed to find benefits; however, 2 RCTs found benefits. One was extremely small4 and the other involved children highly infected with parasites and very low initial levels of hemoglobin.5 Preventive trials have had small samples and inadequate measures of IDA and/or been confounded by other dietary components.3
The study by Lozoff and colleagues6 comprises the largest preventive trial of iron supplementation in infants to date. Furthermore, the investigators used adequate measures of iron status and more comprehensive developmental measures than previous studies. They found no effect on the children’s scores on the Bayley Scales or a test of recognition memory but a benefit was found in speed of information-processing, behavior, and the age of creeping. As planned, the study should have provided definitive answers. It is a tragedy and a classic example of false economy that their funding was reduced and the investigators had to abandon their randomized design and resort to a quasi-experimental approach. The low- and high-iron groups were separated by time and consumed different amounts of cows’ milk. We, therefore, cannot infer with confidence that iron deficiency caused these small differences. Furthermore, as in nearly all studies, high-risk infants (low birth weight or IDA at 6 months) were excluded but may be the most vulnerable and form a large proportion of children in low resource countries.
There is consensus that severe anemia is harmful, and these findings increase the suspicion that IDA affects children’s development. However, considering the expense and difficulties of large treatment programs, there remains an urgent need to know whether mild to moderate anemia affects children’s development and to what extent. The authors correctly call for more RCTs.
 |
FOOTNOTES |
|---|
Received for publication May 2, 2003; Accepted May 2, 2003.
Address correspondence to Sally Grantham-McGregor, FRCP, MD, Center for International Child Health, Institute of Child Health, University College London, 30 Guilford Street, London, United Kingdom WC1N IEH. E-mail: s.mcgregor{at}ich.ucl.ac.uk
|
REFERENCES |
|---|
 TOP REFERENCES |
|---|
1. de Andraca I, WalterT, Castillo M, Pino P, Rivera P, Cobo C. Iron Deficiency Anemia and Its Effects Upon Psychological Development at Pre-school Age: A Longitudinal Study. Nestle Foundation Annual Report. Lausanne, Switzerland: Nestle Foundation; 1990: 53–62
2. Lozoff B, Jimenez E, Hagen J, Mollen E, Wolf AW. Poorer behavioral and developmental outcome more than 10 years after treatment for iron deficiency in infancy. Pediatrics2000; 105(4) . Available at: http://www.pediatrics.org/cgi/content/full/105/4/e51
3. Grantham-McGregor S, Ani A. Review of studies on the effect of iron deficiency on cognitive development in children. J Nutr.2001; 649S –668S
4. Idjradinata P, Pollitt E. Reversal of developmental delays in iron-deficient anemic infants treated with iron. Lancet1993; 341 :1 –4[CrossRef][Web of Science][Medline]
5. Stoltzfus RJ, Kvalsvig JD, Chwaya HM, et al. Effects of iron supplementation and anthelmintic treatment on motor and language development of preschool children in Zanzibar: double blind, placebo controlled study.
BMJ2001; 323
:1
–8
6. Lozoff B, De Andraca I, Castillo M, Smith JB, Walter T, Pino P. Behavioral and developmental effects of preventing iron-deficiency anemia in healthy full term infants. Pediatrics.2003; 112 :845 –854
PEDIATRICS (ISSN 1098-4275). ©2003 by the American Academy of Pediatrics
CiteULike 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
