title: Fortification iron as ferrous sulfate plus ascorbic acid is more rapidly absorbed than as sodium iron EDTA but neither increases serum nontransferrin-bound iron in women.
abstract: The absorption profile of iron fortificants may be a determinant of their ability to generate nontransferrin-bound iron (NTBI) and, thus, their potential safety. Ferrous iron may be absorbed more rapidly than chelated ferric iron, but differences at the fortification level cannot be distinguished with nonisotopically labeled serum iron curves. Using stable isotope appearance curves (SIAC) in serum, we measured iron absorption profiles from FeSO(4) with ascorbic acid (AA) and from NaFeEDTA, as well as the serum hepcidin and NTBI response following the meals. Healthy women (n = 16) were given 6 mg oral iron as labeled FeSO(4) and NaFeEDTA with a maize porridge using a crossover design. SIAC, NTBI, and serum hepcidin were measured over 8 h after the meal. Iron from FeSO(4) plus AA was more rapidly absorbed, resulting in a 35% greater relative AUC during the first 2 h than for NaFeEDTA (P < 0.001). Median (95% CI) fractional iron absorption from the FeSO(4)- and NaFeEDTA-fortified meals was 15.2% (11.0-19.5) and 6.0% (5.0-9.2), respectively (P < 0.001). In response to the FeSO(4)-fortified meal, there was an ~60% increase in median serum hepcidin (P < 0.05) but no significant change in NTBI. There was no significant change in serum hepcidin or NTBI after the NaFeEDTA-fortified meal. SIAC are a useful new tool to compare iron absorption profiles from different iron compounds in fortified foods. Even with the use of a very well absorbed ferrous iron compound, iron fortification in this population does not increase NTBI, suggesting a low risk for adverse health consequences.
authors: Laboratory for Human Nutrition, Institute of Food Science and Nutrition, ETH Zurich, 8092 Zurich, Switzerland.
authors: Barbara
authors: B
authors: Troesch
authors: Ines
authors: I
authors: Egli
authors: Christophe
authors: C
authors: Zeder
authors: Richard F
authors: RF
authors: Hurrell
authors: Michael B
authors: MB
authors: Zimmermann
mesh_terms: D000328:Adult; D000465:Algorithms; D018798:Anemia, Iron-Deficiency / Q000517:prevention & control; D023181:Antimicrobial Cationic Peptides / Q000097:blood; D001205:Ascorbic Acid / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004492:Edetic Acid / Q000009:adverse effects / Q000378:metabolism; D005260:Female; D005290:Ferric Compounds / Q000009:adverse effects / Q000378:metabolism; D005296:Ferrous Compounds / Q000008:administration & dosage*; D005527:Food, Fortified / Q000009:adverse effects / Q000032:analysis*; D006454:Hemoglobins / Q000032:analysis; D064451:Hepcidins; D006801:Humans; D007408:Intestinal Absorption; D007502:Iron Chelating Agents / Q000009:adverse effects / Q000378:metabolism; D007503:Iron Isotopes; D019266:Iron, Dietary / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000378:metabolism*; D007700:Kinetics; D010084:Oxidation-Reduction; D011485:Protein Binding
chemical_list: D023181:Antimicrobial Cationic Peptides; D005290:Ferric Compounds; D005296:Ferrous Compounds; C578702:HAMP protein, human; D006454:Hemoglobins; D064451:Hepcidins; D007502:Iron Chelating Agents; D007503:Iron Isotopes; D019266:Iron, Dietary; C020748:ferrous sulfate; D004492:Edetic Acid; C019179:Fe(III)-EDTA; D001205:Ascorbic Acid