OBJECTIVE The effect of ethanol consumption, either during the pregnancy or lactation period, on the altered metabolism of zinc is not well-defined; consequently, this study was performed to analyze the effect of chronic ethanol exposure on milk consumption, serum, milk, duodenal absorption, fecal and urinary excretion of zinc in dams and offspring during either gestation or lactation in the rat. A complementary study was performed regarding pregnancy outcome. We evaluated testosterone values, the offspring born/litter and several indices such as fertility, viable gestations and the survival index. METHODS To study the effect of chronic alcoholism during gestation or lactation separately, at birth control newborns were cross-fostered to ethanol dams (ED), and the offspring issued from the ethanol treated mothers were cross-fostered to control dams (CD). Thus, three experimental groups of offspring were formed: (i) control offspring receiving no treatment (CO); (ii) offspring exposed to ethanol only during gestation (GO); and (iii) offspring exposed to ethanol only during lactation (LO). All the results were compared with offspring pair-fed groups (PFO) born of the pair-fed dams (PFD). RESULTS Duodenal absorption of zinc increased significantly in LO offspring when the substrate concentrations in the perfusion medium were 25, 75, and 150 microM. A higher faecal excretion in GO pups compared with those with LO exposure and control groups (CO and PFO). The urine excretion of zinc was higher for LO offspring with respect to the other three experimental groups (CO, GO, and PFO). CONCLUSIONS Maternal adaptation resulted in zinc retention, adequate to meet the demands of pup's growth in the face of a lower diet intake. The zinc status in pups is regulated by a higher absorption of zinc and intestinal conservation of endogenous fecal zinc after postnatal ethanol consumption. The increase in urinary zinc excretion could be responsible for decreased serum zinc. However, we found an increase in serum zinc probably due to an increase in the zinc absorption values.