Effect of Commercial Green Tea Beverage Containing Ascorbic Acid on Iron Absorption from a Sodium Ferrous Citrate Preparation.

Abstract

There are reports that green tea does not inhibit iron absorption from chalybeate. However, these reports did not pay sufficient attention to experimental conditions, such as subject age and nutritional status. We therefore determined the effect of a commercially available green tea beverage on iron absorption from a sodium ferrous citrate preparation (containing 100 mg iron) in 50 healthy female students (aged 18-24 years old) with similar nutritional status. The subjects were divided into 4 groups: controls, those drinking a commercial green tea beverage containing 110 mg tannin and 47.6 mg ascorbic acid (tea), those drinking chalybeate (Fe), and those drinking chalybeate with the commercial green tea beverage (Fe+tea). We examined serum Fe, total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC) and ferritin. Three hours after administration in the Fe and the Fe+tea groups, the serum Fe level was significantly higher (P<0.001) and UIBC was significantly lower (P<0.001) than in the control and the tea groups. The serum Fe and UIBC in the Fe group were not significantly different from thoe in the Fe+tea group. From these results, we conclude that in young women, iron absorption from sodium ferrous citrate is not inhibited by commercially available green tea beverages containing ascorbic acid.