Bioavailable iron density in French and Spanish meals

Iron absorption from two typical French meals and three typical Spanish meals was measured, using the extrinsic tag technique (with 55Fe and 59Fe) on French and Spanish volunteers. The total iron absorption coefficient varied up to three-fold (between 3.4 and 11.4 per cent) according to the contents of haem and non-haem iron and the presence of non-haem iron absorption enhancers and inhibitors. Expressed for iron absorption of 40 per cent of the reference dose (corresponding to subjects with theoretical depleted iron stores), those coefficients varied up to four-fold (between 4.9 and 18.9 per cent). The bioavailable nutrient density ranged from 0.30 to 0.77 mg/1000 kcal in subjects with good iron stores and from 0.50 to 1.12 mg/1000 kcal for subjects with theoretical depleted iron stores. This low bioavailable iron density enabled understanding of why iron balance is especially critical in women of childbearing age in industrialized countries, where iron enrichment of food is not practised.