A woman loses additional iron during her reproductive life: (i) during each menstrual cycle 30-60 ml of blood is lost, which involves a monthly loss of 15-30 mg (269-537 micromol) iron; (ii) during pregnancy the fetus, placenta, and loss during parturition drain the mother of over 500 mg (9 mmol) iron, which would require an increase in the daily absorption by 2 mg (36 micromol); and (iii) during lactation, there is an additional daily loss of 1.5 mg (27 micromol) iron. Owing to such losses, women--even in Western countries-have low iron stores.
Jun88 
