The influence of riboflavin deficiency on absorption and liver storage of iron in the growing rat.

1. Iron absorption was measured in weanling riboflavin-deficient (RD) rats or weight-matched (WM) controls fed on appropriate diets for 7 weeks. Concentrations of radio-Fe (59Fe) in plasma were monitored every 30 min for 4 h following intragastric administration. 2. Total Fe absorption in RD rats was significantly lower than that in WM controls, and the tissues of the stomach and small intestine of RD rats retained significantly (P less than 0.001) more 59Fe by comparison with WM groups. 3. In a separate experiment, ferritin-Fe concentrations were measured in the livers of four groups of rats (ad lib. (C), pair-fed (PF) and WM controls and RD) at day 0, and subsequently at days 14, 21, 28, 35 and 49. 4. Liver ferritin-Fe concentration was significantly lower (P less than 0.05) in RD rats than in all other controls after 3 weeks on the respective diets and remained lower for the remainder of the experiment.