(PTFS05-01-23) Early Iron Supplementation of Exclusively Breastfed Infants in Rural Gambia: A Randomised Double-Blinded, Placebo-Controlled Trial

Objectives: The World Health Organization recommends daily iron supplementation in children aged 6–23 months living in settings with high prevalence of anaemia. However, in low-income settings, iron deficiency is very common before 6 months of age in exclusively breastfed infants. We assessed the effect of early iron supplementation (from 6 weeks – 6 months of age) on multiple iron markers, inflammation, illnesses and growth.

Methods: We recruited 101 healthy, exclusively breastfed infants between 6 to 10 weeks of age from vaccination clinics and local communities and randomised them to daily supplementation with iron (7.5mg, as ferrous sulphate; n=50) or placebo (n=51). Participants were visited and supplemented daily for 98 days. Effects were reported as crude absolute differences in means for normally distributed variables or crude relative differences in geometric means for log-normally distributed variables. The trial was approved by a joint Gambia/UK ethics committee and registered with clinicaltrials.gov (NCT04751994).

Results: Iron supplementation led to increased concentrations of serum iron (2.5μmol/L; 95%CI: 0·6 to 4·3μmol/L, p=0.0091, primary outcome); ferritin by 111% (OR: 2·11, 95%CI: 1·49 to 2·98, p=0.0005); haemoglobin (0.6 g/dL; 95%CI: 0·2 to 1·0 g/dL, p=0.0072); reticulocyte haemoglobin (2·8pg; 95%CI: 1·6 to 3·9pg, p< 0·0005); transferrin saturation by 45%; (OR: 1·45 95%CI: 1·19 to 1·78, p=0.0005) and hepcidin by 79% (OR: 1·79 95%CI: 1·20 to 2·66, p=0.0044). Iron supplementation decreased serum soluble transferrin receptor concentration by −7.2% (OR: 0·93, 95%CI: 0·90 to 0·96 p=0.0005) and UIBC (−8·7μmol/L; 95%CI: −13·1 to −4·3μmol/L, p=0.0005). There were no deaths, and no differences in rates of adverse events or maternally reported episodes of illness. Iron supplementation did not affect growth.

Conclusions: Iron supplementation in exclusively breastfed rural Gambian infants was highly efficacious in enhancing iron status. Large-scale studies are required to determine iron supplementation’s effect on functional and safety outcomes to inform implementation strategies in low- and middle-income settings.

Funding Sources: UK Department for International Development, Medical Research Council UK, National Institute for Health and Care Research, Wellcome Trust.