Iron fortified follow on formula from 9 to 18 months improves iron status but not development or growth: a randomised trial

Aims - Iron deficiency anaemia is associated, in observational studies, with developmental disadvantage. This study tested the hypothesis that feeding iron supplemented formula from 9 to 18 months of age would improve developmental performance. Subjects and methods - 493 healthy children aged 9 months being fed pasteurised cows' milk were recruited from three UK centres. They were randomised to: cows' milk as before, formula containing 0.9 mg/litre iron, or formula containing 1.2 mg/litre irons until 18 months of age. Bayley mental and psychomotor developmental indices were measured at 18 months, as were growth and haematological indices. Results - Children fed iron fortified formula had higher plasma ferritin concentrations, but there were no significant intergroup differences in development or growth. Conclusions - There are no developmental or growth advantages in children given iron supplemented formulas but a benefit for a minority who were anaemic, or the possibility that a benefit may emerge at a later age, cannot be excluded.