Iron supplementation appears to improve motor and language development in iron deficient preschool children, reports the British Medical Journal this week.

Researchers from the Centre for Human Nutrition at the Johns Hopkins University in the US set out to measure the effects of iron supplementation and anthelmintic treatment on iron status, anaemia, growth, morbidity, and development of children aged 6-59 months.

They studied 614 pre-school children aged 6-59 months in Zanzibar. Results of the double blind, placebo controlled trial showed that before intervention, anaemia was prevalent and severe, and geohelminth infections were prevalent and lightPlasmodium falciparum infection was nearly universal.

Iron supplementation significantly improved iron status, but not haemoglobin status and improved language development by 0.8 (95% confidence interval 0.2 to 1.4) points on the 20 point scale. Iron supplementation also improved motor development, but this effect was modified by baseline haemoglobin concentrations (P=0.015 for interaction term) and was apparent only in children with baseline haemoglobin concentrations inferior to 90 g/l.

The researchers concluded that iron supplementation improved motor and language development of preschool children in rural Africa. The effects of iron on motor development were limited to children with more severe anaemia (baseline haemoglobin concentration inferior to 90 g/l). Mebendazole had a positive effect on motor and language development, but this was not statistically significant.

Full findings are published in the current issue of the British Medical Journal.