The effect of different iron fortificants on iron absorption from iron-fortified rice

Iron absorption from rice fortified with different iron fortificants, e.g., ferrous sulfate (FeS04), sodium iron EDTA (NaFeEDTA), ferrous fumarate (FeFum), and ferrous bisglycinate (FeBis) was determined using an in vitro enzymatic digestion method simulating conditions in the small intestine and an in vivo method using radioisotope techniques. The in vitro method showed that the percentage of dialyzable iron from NaFeEDTA (15.7 +/- 0.9) and FeS04-fortified rice (13.2 +/- 1.5) was significantly greater than that from FeFum (6.4 +/- 0.6; p < .05) and FeBis fortified rice (3.3 +/- 0.8; p < .05). Iron absorption in vivo was investigated from FeS04 and NaFeEDTA fortified rice with and without fish and vegetables in 10 borderline iron-deficient subjects. Iron absorption (mg) from NaFeEDTA fortified rice (0.44 +/- 0.11) was significantly greater than from FeS04-fortified rice (0.22 +/- 0.05; p < .05) and the unfortified rice (0.17 +/- 0.02; p < .05). Iron absorption (mg) from a meal consisting of iron-fortified rice, fish, and vegetables was significantly greater from NaFeEDTA (0.88 +/- 0.24) and FeS04 (0.67 +/- 0.10) -fortified rice than from the unfortified rice (0.41 +/- 0.08; p < .05). This study concluded that both NaFeEDTA and FeSO4 are effective iron fortificants for rice. The binder used in the study may have a significant role in the release of iron from iron-fortified rice for absorption. Further studies on the use of other binders to maximize iron release and minimize iron loss during cooking should be conducted to improve iron absorption from the fortified rice/rice-fish-vegetable meals. Results from this study can be used as a basis for food iron fortification programs as well as in the establishment of recommended dietary allowances for iron among Filipinos.