Iron absorption from a breakfast cereal: effects of EDTA compounds and ascorbic acid

Sodium iron ethylenediaminetetracetic acid (NaFeEDTA) has been recommended for food fortification programmes to improve iron status but its performance in commercial products has not been evaluated. The effect of EDTA on iron absorption from fortified cornflakes, given as part of a typical Western breakfast, was determined in a double-blind randomised study with 20 non-anaemic female volunteers, using experimentally prepared iron compounds, enriched with 58Fe, and faecal monitoring. Five meals were compared: hydrogen reduced iron, hydrogen reduced iron plus Na2EDTA (molar ratio EDTA:Fe 1:2), hydrogen reduced iron plus NaFe(III)EDTA at two different molar ratios (EDTA:total Fe 1:3 and 1:2), and hydrogen reduced iron plus 15 mg ascorbic acid (ascorbic acid:Fe 1.3:1). The iron and EDTA compounds were accurately weighed into gelatine capsules and taken with unfortified cornflakes, semi-skimmed milk and tea on two consecutive days; the iron dose per meal was 3.75 mg. Iron absorption from all five test meals was measured in each volunteer with a minimum wash-out period of 2 weeks between tests. Geometric mean iron absorption (%) from the 5 tests was 14.1, 17.6, 20.6, 24.4 and 17.5 respectively (equivalent to 0.5-0.9 mg absorbed iron). There was a significantly higher iron absorption from the mixture of reduced iron and NaFe(III)EDTA (EDTA:Fe 1:2) than from reduced iron alone (p = 0.014). It is not known whether the higher absorption was from reduced iron or NaFeEDTA or both. Absorption was not increased significantly with NaFe(III)EDTA (EDTA:Fe 1:3), Na2EDTA (EDTA:Fe 1:2) or ascorbic acid (15 mg).