Figure 3.

Effect of gastric digestion on supernatant iron and iron uptake in Caco-2 cells. Ferric ammonium citrate (FAC) or NP-FePO₄ (30 µM Fe) was digested at pH 2 for varying times (A) or digested at varying pH for 1 hour (B) and supernatant iron determined at the end of gastric digestion. Caco-2 cells were exposed to digested FAC or NP-FePO₄ (30 µM Fe) for 24 h and measured for cell ferritin formation (C,D). Data values are expressed as the means of two independent experiments (n = 3 per experiment, ± standard error of the mean (SEM)). One-way repeated measures analysis of variance (ANOVA) with Tukey’s multiple comparisons test was used to compare differences in iron uptake between iron treatment (FAC or NP-FePO₄) with time or pH. Different letters indicate statistically significant differences (p < 0.05).