Effect of restricted maternal zinc intake on zinc absorption in infant rhesus monkeys

One compensatory mechanism for marginal Zn intake may be enhanced absorption of Zn. While there is some experimental evidence to support this hypothesis from rodent models, there are few data from higher mammalian species. Such a compensatory mechanism of enhanced Zn absorption could be of value to the neonate, as poor Zn nutriture during early life has severe consequences on growth and development. The authors have investigated the absorption of Zn by infant Rhesus monkeys born to control and Zn-restricted mothers. Fasted infant monkeys (100 d) from mothers fed a 100 or 4 ppm Zn diet were intubated with an infant formula containing Zn-65. Whole body radioactivity was counted immediately after intubation and on days 10 and 17 post-intubation. Day 10 data were used to calculate apparent absorption values. Regardless of dietary group, apparent Zn absorption as high, ranging from 30-60% of the dose fed. While there was not a marked difference between the two groups in the groups in the dose absorbed, an inverse correlation was noted between infant body weight and Zn absorption. An inverse correlation was found for plasma Zn concentration and apparent Zn absorption. These results suggest that body weight and plasma Zn level, as related to Zn status and growth rate, may be predictors of Zn absorption