The Utilization of Iron from Different Foods by Normal Young Rats

Abstract
When normal young rats were fed daily 0.002 mg iron per gm of body weight from different sources and hemoglobin formation and iron retention in a 6-week period were used as the criteria of “availability,” it was found that: The iron of whole wheat flour was about equal in availability to that of ferric chloride. The iron of beef liver was almost but not quite as available as that of ferric chloride. The iron of the other food materials tested (beef muscle, egg yolk, uncooked and cooked kale, and uncooked and cooked spinach) was less available than that of beef liver; the differences among these supplements were small. In general the order of “iron availability” of these different foods was the same as that observed in studies of hemoglobin regeneration in anemic rats, but the differences were smaller. When normal young rats were given diets containing readily available sources of iron (I) whole wheat flour, (II) half whole wheat, half unenriched patent flour, (III) unenriched patent flour, (IV) unenriched patent flour plus ferric chloride, for a 6-week period, it was found that: Hemoglobin production and iron storage were improved when the level of intake of iron averaged slightly more than 0.002 mg per gm of body weight daily (Diet I). Levels of iron averaging lower than 0.002 mg iron per gm of body weight daily were insufficient to bring about good hemoglobin production; a level slightly lower resulted in a small hemoglobin gain (Diet II) but when the level of iron averaged below 0.001 mg (Diet III) no gain was observed in 6 weeks. Levels of iron averaging lower than 0.002 mg iron per gm of body weight were insufficient to bring about much increase in the iron content per gm of rat in 6 weeks; a slightly lower level resulted in a slight increase (Diet II), but when the level of iron averaged below 0.001 mg (Diet III) a decrease was observed.