An explanatory in vitro study on the effect of copper gluconate on ferrous gluconate absorption in a Caco-2 cell model

Anemia is one of the most prevalent nutritional diseases worldwide, primarily caused by iron deficiency. Poor absorption of dietary iron results from its low bioavailability and interactions with food components. In that context, dietary iron supplementation has been widely used to treat iron deficiency anemia. For many years, there has been growing interest in exploring various types of iron supplementation to improve the efficacy of iron supplements, satisfying iron needs and lowering side effects. This study aimed to generate preliminary data regarding the effect of co-administration of copper on ferrous gluconate intestinal absorption. To address this question, the iron absorption from ferrous gluconate was measured using the Caco-2 cell model, by determining apparent permeability (Papp) of ferrous gluconate with or without presence of copper gluconate. These results are based on a single experiment and should be interpreted accordingly. Under experimental conditions, a 4.9-fold increase in iron Papp values was seen when ferrous gluconate was incubated with copper gluconate. These preliminary findings suggest that co-administration of ferrous gluconate with copper gluconate may enhance iron absorption and would provide an additional and valuable benefit for treating iron deficiency compared to conventional iron supplements with iron alone.