ABSTRACTCentury soybeans were grown in a greenhouse and labeled by stem injection of iron‐59. The intrinsically labled soybean hulls were incorporated into bread rolls and fed in mixed meals containing beef to six free‐living female volunteers. Iron‐59 retention, measured by whole body counting of these volunteers, was compared with retention from similar meals containing extrinsically labeled soybean hulls or bakery grade ferrous sulfate. Iron‐59 retention averaged 23% from meals containing the intrinsically labeled soybean hulls, 18% from meals containing extrinsically labeled soybean hulls, and 22% from meals containing bakery grade ferrous sulfate. There were no statistically significant differences in retention among the various iron sources, indicating that soybean hulls were an excellent source of iron for bread enrichment.