Iron absorption from a cereal-based meal containing cane sugar fortified with ascorbic acid

Abstract

1. The feasibility of improving iron nutrition by fortifying cane sugar with ascorbic acid was studied.2. The absorption of Fe added to maize-weal porridge was measured in 116 volunteer multiparous Indian women using the radio-Fe erythrocyte utilization method. The meals were fed with and without tea or coffee and with and without varying amounts of ascorbic acid.3. The mean absorption of Fe from maize-meal porridge was very low (3.8 %), being even further reduced (2.1 %) when tea was drunk with the meal.4. The addition of 50 or 100 mg ascorbic acid to maize-meal porridge caused approximately a 10-fold increase in Fe absorption. The increase was much less when tea was present, being 2-fold and 5-fold with 50 and 100 mg ascorbic acid respectively. The inhibitory effect of tea on Fe absorption could, however, be overcome by giving larger doses of ascorbic acid (250 and 500 mg).5. When contaminating Fe (2.5 mg) in the form of labelled rust (Fe2O3) or ferric hydroxide was added to maize-meal porridge it was poorly absorbed (mean values were 0.01 % and 1.5 % respectively). The addition of 100 mg ascorbic acid increased the mean Fe absorption rates to 0.5 % and 6.7 % with Fe2O3 and Fe(OH)3 respectively. Fe(OH)3 was found to be absorbed about half as well as the intrinsic Fe present in maize-meal porridge.6. It is concluded that ascorbic acid is capable of improving Fe absorption from a cereal source. It can partially overcome the inhibitory effect of tea and might be expected to facilitate the absorption of at least some forms of Fe that may contaminate food.