Flour fortification with iron has no impact on anaemia in urban Brazilian children

Objective: To verify the impact of flour fortification on anaemia in Brazilian children. The survey also investigated the role of Fe deficiency as a cause of anaemia and estimated the bioavailability of the Fe in the children's diet. This local study was complemented by a nationwide survey of the types of Fe compounds added to flour. Design: Series of population-based surveys conducted in 2004 (baseline study), 2005, 2006 and 2008. Setting: Pelotas, Rio Grande do Sul, Brazil. Subjects: Children under 6 years of age residing in the urban area of the city of Pelotas, Southern Brazil (n 507 in 2004; n 960 in 2005; n 893 in 2006; n 799 in 2008). In 2008, a sub-sample of children (n 114) provided venous blood samples to measure body Fe reserve parameters (ferritin and transferrin saturation). Results: We found no impact of fortification, with an increase in anaemia prevalence among children under 24 months of age. Hb levels decreased by 0.9 g/dl in this age group between 2004 and 2008 (10.9 g/dl to 10.0 g/dl; P < 0.001). Roughly 50% of cases of anaemia were estimated to be due to Fe deficiency. Half of the mills surveyed used reduced Fe to fortify wheat flour. Total Fe intake from all foodstuffs was adequate for 88.6% of the children, but its bioavailability was only 5%. Conclusions: The low bioavailability of the Fe compounds added to flours, combined with the poor quality of children's diets, account for the lack of impact of mandatory fortification.