title: Effect of ascorbic acid and particle size on iron absorption from ferric pyrophosphate in adult women.
abstract: The effects of added ascorbic acid and particle size on iron absorption from ferric pyrophosphate were evaluated in adult women (9-10 women/study) based on erythrocyte incorporation of iron stable isotopes (57Fe or 58Fe) 14 days after administration. Three separate studies were made with test meals of iron-fortified infant cereal (5 mg iron/meal) and the results are presented as geometric means and relative bioavailability values (RBV, FeSO4 = 100%). The results of study 1 showed that iron absorption was significantly lower from ferric pyrophosphate (mean particle size 8.5 microm) than from FeSO4 in meals without ascorbic acid (0.9 vs. 2.6%, p < 0.0001, RBV 36%) and in the same meals with ascorbic acid added at a 4:1 molar ratio relative to fortification iron (2.3 vs. 9.7%, p < 0.0001, RBV 23%). Ascorbic acid increased iron absorption from ferric pyrophosphate slightly less (2.6-fold) than from FeSO4 (3.7-fold) (p < 0.05). In studies 2 and 3, RBV of ferric pyrophosphate with an average particle size of 6.7 microm and 12.5 pm was not significantly different at 52 and 42% (p > 0.05), respectively. In conclusion, the addition of ascorbic acid increased fractional iron absorption from ferric pyrophosphate significantly, but to a lesser extent than from FeSO4. Decreasing the mean particle size to 6.7 microm did not significantly increase iron absorption from ferric pyrophosphate.
authors.affiliation: Laboratory for Human Nutrition, Institute of Food Science and Nutrition, Swiss Federal Institute of Technology (ETH) Zurich, Switzerland.
authors.forename: Meredith C
authors.initials: MC
authors.lastname: Fidler
authors.forename: Lena
authors.initials: L
authors.lastname: Davidsson
authors.forename: Christophe
authors.initials: C
authors.lastname: Zeder
authors.forename: Thomas
authors.initials: T
authors.lastname: Walczyk
authors.forename: Irene
authors.initials: I
authors.lastname: Marti
authors.forename: Richard F
authors.initials: RF
authors.lastname: Hurrell
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage*; D001682:Biological Availability; D011756:Diphosphates / Q000737:chemistry / Q000493:pharmacokinetics*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005296:Ferrous Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D007501:Iron / Q000737:chemistry / Q000493:pharmacokinetics*; D007503:Iron Isotopes / Q000097:blood; D019266:Iron, Dietary / Q000008:administration & dosage / Q000493:pharmacokinetics*; D010316:Particle Size; D013997:Time Factors
chemical_list: D011756:Diphosphates; D005296:Ferrous Compounds; D007503:Iron Isotopes; D019266:Iron, Dietary; C020748:ferrous sulfate; D007501:Iron; D001205:Ascorbic Acid; C049051:ferric pyrophosphate