Oral Iron Absorption Test in Patients on CAPD: Comparison of Ferrous Sulfate and a Polysaccharide Ferric Complex

Abstract

We prospectively compared the absorption of ferrous sulfate to that of a polysaccharide ferric complex (Niferex®) in 5 healthy controls and 7 stable patients on continuous ambulatory peritoneal dialysis (CAPD). All study subjects received an equivalent of 150 mg of elemental iron of either preparation, in a random fashion. After a baseline fasting serum iron level was obtained, the serum iron concentration was measured at 2 h in the control group and at 2 and 4h in the CAPD patients. One to 2 months later, all study subjects received the alternative iron compound and were studied in an identical manner. A significant rise in serum iron was only observed in the healthy subjects after the ingestion of ferrous sulfate and not Niferex (ferrous sulfate 102 ± (SE) 9 vs. 142 ± 7 Mg/dl, p = 0.0005; Niferex 96 ± (SE) 10 vs. 102 ± 12 mg/dl; baseline vs. 2 h, respecitvely). The absorption of both compounds was poor in the patients on CAPD, with the 2- and 4-hour serum iron levels not significantly higher than the baseline values (ferrous sulfate 73 ± 7 vs. 107 ± 21 vs. 109 ± 21 mg/dl, p = NS; Niferex 57 ± 11 vs. 65 ± 14 vs. 60 ± 11 mg/dl, p = NS; baseline vs. 2 vs. 4 h, respectively). Our data suggest that the absorption of both ferrous sulfate and ferric polysaccharide complex is poor in patients on CAPD.

Characterization of Caco-2 and HT29-MTX cocultures in an in vitro digestion/cell culture model used to predict iron bioavailability☆

“…Factors that inhibit iron uptake, such as phytic and tannic acid, have also been replicated [6]. The in vitro iron bioavailability of iron supplements (a polysaccharide-iron complex and an FeSO 4 preparation) agreed with results from a closely matched human study [7,8].…”

Reference distributions for serum iron and transferrin saturation: A comparison of a large cohort to the world's literature

“…A total of 45 publications were identified that contained information on serum iron in apparently healthy individuals (6,(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)39,(41)(42)(43)(44)(45)(46)(48)(49)(50)(51)(52)(53)(54)(55)(56). Five did not provide basic information or sufficient numerical data to permit statistical analysis (9,28,36,38,51).…”

Anemia during the Predialysis Period: A Key to Cardiac Damage in Renal Failure

“…In a recent Dutch study [63], only 1% of the patients using EPO on peritoneal dialysis and only 19% using EPO on hemodialysis were receiving intravenous iron, whereas the majority of these patients were receiving oral iron. Oral iron, however, is poorly absorbed in chronic renal failure [64, 65, 66]and is much less effective than the intravenously administered form in hemodialysis [57, 58]or in peritoneal dialysis [67, 68]patients. Perhaps these physicians fear the side effects of intravenous iron.…”