Utilization of Iron from an Animal-Based Iron Source Is Greater Than That of Ferrous Sulfate in Pregnant and Nonpregnant Women

Heme iron absorption during pregnancy and the role of hepcidin in regulating dietary heme iron absorption remains largely unexplored The objective of this research was to examine relative differences in heme (animal based) and nonheme (ferrous sulfate) iron utilization This study was undertaken in 18 pregnant (ages 16-32 y wk 32-35 of gestation) and 11 nonpregnant women (ages 18-27 y) Women were randomly assigned to receive both an animal based heme meal (intrinsically labeled Fe-58 pork) and labeled ferrous sulfate (Fe-57) fed on alternate days Blood samples obtained 2 wk postdosing were used to assess iron status indicators and serum hepcidin and iron utilization based on R BC incorporation of iron isotopes Heme iron utilization was significantly greater than nonheme iron utilization in the pregnant 147 7 +/- 144 vs 404 +/- 13 2%) and nonpregnant women (50 1 +/- 148 vs 153 9 +/- 7%) Among pregnant women utilization of nonheme iron was associated with iron status as assessed by the serum transferrin receptor concentration (P = 0 003 r(2) = 0 431 In contrast heme iron utilization was not influenced by maternal iron status In the group as a whole women with undetectable serum hepcidin had greater nonheme iron utilization compared with women with detectable serum hepcidin (P = 0 02 n = 29) however there were no significant differences in heme iron utilization Our study suggests that iron utilization from an animal-based food provides a highly bioavailable source of dietary iron for pregnant and nonpregnant women that is not as sensitive to hepcidin concentrations or iron stores compared with ferrous sulfate J Nutr 140 2162-2166 2010