ABSTRACT
The effect of daily administration for nine weeks of the natural female sex hormones oestradiol benzoate and progesterone [alone and combined] as well as the synthetic female sex hormones norethisterone and ethinyl oestradiol [alone or combined] on oral iron absorption was investigated in the rabbit and the rat. Oral iron absorption was assessed through the study of post absorption plasma iron tolerance curves [both chemical and radioactive], red blood cell uptake of radio-iron and whole body retention of radio-iron. The results showed that in the rabbit the natural female sex hormones led to a decrease of oral iron absorption. On the other hand, synthetic female sex hormones, norethisterone alone or combined with ethinyl oestradiol, increased oral iron absorption in the rat. Yet the combination of both synthetic female sex hormones did not affect oral iron absorption in the rabbit. These results were statistically analysed and discussed