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United States Department of Agriculture

Agricultural Research Service

Title: A Comparison of Iron Availability from Commercial Iron Preparations Using An in Vitro Digestion/caco-2 Cell Culture Model

Authors
item Glahn, Raymond
item Rassier, Mark - MARSHFIELD CLINIC
item Goldman, Matthew - CORNELL UNIVERSITY
item Lee, Olivia - CORNELL UNIVERSITY
item Cha, Jennifer - CORNELL UNIVERSITY

Submitted to: Journal of Nutritional Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 9, 1999
Publication Date: N/A

Interpretive Summary: Commercial preparations of ferrous sulfate, ferrous gluconate, ferrous fumarate and a polysaccharide-iron complex are commonly prescribed by physicians for iron deficient patients. A major group of patients who are chronically iron-deficient are those with kidney disease requiring dialysis therapy. For reasons unknown, ingested iron is poorly absorbed by these patients. The objectives of this study were to compare iron availability from these forms of iron using an in vitro digestion/Caco-2 cell culture model. Since dialysis patients must consume phosphate binding agents (calcium carbonate and calcium acetate) with every snack or meal, we determined if these agents inhibited iron availability when digested simultaneously with the iron supplement. The results showed that significantly more iron was taken up from the ferrous sulfate, ferrous gluconate and ferrous fumarate relative to the polysaccharide-iron complex. .Similar results comparing ferrous sulfate and the polysaccharide-iron complex have been observed in humans. Also, less iron was taken up from digests with calcium carbonate relative to calcium acetate even though similar amounts of soluble iron were observed in these experiments. The results indicate that when iron supplements and phosphate binders are consumed simultaneously, calcium acetate may be the preferred phosphate binder in order to maximize iron availability.

Technical Abstract: The objectives of this study were to compare iron availability from commercial preparations of FeSO4, ferrous gluconate, ferrous fumarate and a polysaccharide-iron complex using an in vitro digestion/Caco-2 cell culture model. Also, we sought to determine if phosphate binding agents (calcium carbonate and calcium acetate) inhibited iron availability from an oral iron supplement when digested simultaneously. Caco-2 cell ferritin formation following exposure to simulated gastric and intestinal digests of the iron supplements was used as a measure of iron uptake and availability. Plates without cell monolayers were included in each replication of the experiment in order to measure the total amount of soluble iron which resulted from the in vitro digestion. Significantly more iron was taken up from the FeSO4, ferrous gluconate and ferrous fumarate relative to the polysaccharide-iron complex. Similar results comparing FeSO4 and the polysaccharide-iron complex have been observed in humans. Also, less iro was taken up from digests with calcium carbonate relative to calcium acetate even though similar amounts of soluble iron were observed in these experiments. The results indicate that when iron supplements and phosphate binders are consumed simultaneously, calcium acetate may be the preferred phosphate binder in order to maximize iron availability.

Last Modified: 8/22/2014
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