NaFeEDTA is a promising fortificant for use in plant foods, because it is less susceptible to
iron absorption inhibitors and has fewer undesirable impacts on sensory quality than
ferrous sulfate. However, the hypothesis that
iron absorption from
NaFeEDTA is effectively downregulated in
iron-overload conditions has not been thoroughly tested. Therefore, the objective of this study was to compare downregulation of
iron absorption from
ferrous sulfate and
NaFeEDTA in intact
iron-loaded rats. Male Sprague-Dawley rats were fed diets containing either
ferrous sulfate (35 mg Fe per 1 kg diet) or elemental
iron (30,000 mg Fe per 1 kg diet) for 29 d to achieve basal or
iron-loaded status. While
body weights and
hemoglobin concentrations were the same for basal and
iron-loaded rats, nonheme-
iron concentrations in liver, spleen, and kidney were all significantly higher in
iron-loaded rats, indicating elevated
iron status. Percentage of
iron absorption from (59)Fe-labeled
ferrous sulfate and
NaFeEDTA, determined from whole-body retention of (59)Fe activity, was 64.7 and 49.4% in basal rats but decreased to 12.8 and 10.2% in
iron-loaded rats, respectively. The reductions in percentage of
iron absorption from both
iron sources in rats as a result of
iron loading were comparable (about -80% for both
iron sources). Our results suggest that
iron absorption from
NaFeEDTA and
ferrous sulfate is downregulated to a similar extent in
iron-loaded rats. Hence,
NaFeEDTA is no more likely than
ferrous sulfate to exacerbate
iron overload in subjects with adequate body
iron stores.