1. Zinc metabolism has been studied in a group of undernourished, slum-dwelling, lactating women in Manaus, Brazil, by means of modified metabolic balance techniques and the stable isotope 67Zn. 2. The subjects were found to be consuming a diet which provided an average of 34% of the recommended dietary allowance for lactating women, but six of the seven appeared to achieve Zn balance. In five of the subjects u...