Mean incremental changes in serum iron concentrations between tablet and powdered supplements. Mean (± SEM) incremental changes in serum iron concentration in pregnant subjects over 8 hours after administration of either 27 mg of iron from ferrous fumarate in a traditional tablet supplement or 30 mg of iron from micronized dispersible ferric pyrophosphate in powdered supplement sprinkled over a standard meal. n = 17. The curve was adjusted for basal (diurnal) variation and the iron content of the standardized meal. There was a significant difference (p = 0.0003) between the relative bioavailability (as measured using AUC) of the iron in tablet supplement (41.8 ± 45.9 μmol·h/L) when compared to the iron in the powdered supplement (10.0 ± 43.3 μmol·h/L). The data were analyzed with the use of mixed-model repeated-measures with age, gestational age, ferritin concentration and parity as fixed effects and subject as the repeated effect. The pair-wise differences of least-square means of the treatments were tested with the use of Tukey-Kramer p value adjustments.