In a setting of low anaemia risk, daily low-dose iron supplements do not appear to have any effect on psychomotor development in breastfed infants between 4 and 9 months, as shown in a study.
A total of 221 healthy singleton infants (50.2 percent female) who were born at term with birth weight >2,500 g and who were exclusively or predominantly breastfed (>50 percent) and did not have anaemia (haemoglobin >10.5 g/dL) were included in the study. These infants were randomly assigned to receive iron (micronized microencapsulated ferric pyrophosphate) at 1 mg/kg or placebo (maltodextrin) once daily from age 4 to 9 months.
Psychomotor development, the primary outcome, was assessed by motor score of Bayley Scales of Infant and Toddler Development III at 12 months, adjusted for gestational age, sex, and maternal education. Cognitive and language scores at 12 months; motor, cognitive, and language scores at 24 and 36 months; iron deficiency (serum ferritin <12 ng/mL) and iron deficiency anaemia (iron deficiency and hemoglobin <10.5 g/dL) at 12 months were also evaluated.
The intention-to-treat analysis consisted of 200 infants (90 percent; mean age 12.4 months), including 104 in the iron group and 96 in the placebo group. The motor score at 12 months did not significantly differ between the two treatment groups (mean difference [MD], −1.07 points, 95 percent confidence interval [CI], −4.69 to 2.55), as did the cognitive score (MD, −1.14, 95 percent CI, −4.26 to 1.99), or the language score (MD, 0.75, 95 percent CI, −2.31 to 3.82).
The motor, cognitive, and language scores remained similar between the iron and placebo groups at 24 and 36 months.
Finally, iron supplementation fell short of reducing the risk of iron deficiency (relative risk [RR], 0.46, 95 percent CI, 0.16–1.30) or iron deficiency anaemia (RR, 0.78, 95 percent CI, 0.05–12.46) at 12 months when compared with placebo.