Iron supplemented formula milk related to reduction in psychomotor decline in infants from inner city areas: randomised study

British Medical Journal, March 13, 1999 by J Williams, A Wolff, A Daly, A MacDonald, A Aukett, I W Booth

Comparison with previous studies--Our findings support previous studies of supplementation with oral iron in children with iron deficiency anaemia, where an improvement in developmental performance was noted.[6 7 12] Moffatt and colleagues conducted a similar longitudinal cohort study to our own and showed a developmental advantage at 9 and 12 months, which was no longer detectable at 15 months of age.[8] The transient nature of the effect may have been due to differences in the timing, duration, and mildness of the iron deficiency compared with our study group.

Basis of the developmental advantage--The Griffiths scale has been well validated, and the subscales provide useful insights into the basis of the differences in developmental scores.[10 13] In our study the major difference was in the personal and social subscale. This supports the view that iron deficiency anaemia may exert its effects on developmental performance by alterations in affect, thereby making a child clingy, lethargic, irritable, and listless,[5] and leading to impaired learning skills.

Implications of the study--We acknowledge that it is difficult to quantify precisely the developmental advantage in the infants receiving iron supplemented formula milk, but neverthless believe that this study has a number of important implications. Firstly, it confirms the well recognised observation that socioeconomic deprivation places infants at increased risk of adverse developmental outcomes.[14 15] Secondly, this developmental deficit seems, in part, to be nutritionally mediated. Thirdly, iron deficiency anaemia is common in high risk populations,[14] and both this and the developmental disadvantage are susceptible to a simple intervention: the provision of an iron supplemented formula milk in place of cows' milk.

Breast milk is clearly the milk of choice for the developing infant.[16] Our study suggests that in those mothers who find breast feeding impractical, iron supplemented formula milk seems to be effective and acceptable, and benefits high risk infants and children up to the age of at least 18 months.[15]

Key messages

* Iron deficiency anaemia is common in infants from inner cities who are given unmodified cows' milk in the first year of life

* Giving an infant iron supplemented formula milk instead of cows' milk not only prevents anaemia but reduces the decline in developmental performance observed in those given only cows' milk

* An iron supplemented formula milk rather than cows' milk should be provided free of charge for infants up to the age of 18 months who are living in inner cities and who are not receiving breast milk

We thank the health visitors at Nechells Health Centre for their help, Dr P Davies for his statistical advice, and Dr M Huntley for advice on the Griffiths scales. Contributors: IWB, AMacD, and AA had the original idea for the study, initiated it, and supervised its conduct. AD carried out the dietary intervention and data collection. TW took part in the developmental assessment and the preliminary data analyses. JW took part in the developmental assessment, collated and analysed the data and, with IWB, participated in writing the paper. IWB and JW will act as guarantors for the paper.