Folate depletion secondary to iron deficiency in the neonatal rat

Two experiments were performed to investigate the effect of dietary iron deficiency during reproduction on folate status in rat dams and pups. In experiment 1, twenty pregnant Sprague-Dawley rats (190-200 g) were fed one of two diets (8 ppm Fe, 1 ppm folate or 250 ppm Fe, 1 ppm folate) throughout gestation and until day 18 of lactation when dams and their pups (seven per litter) were killed. Although there was no effect of iron deficiency on dam folate status, iron-deficient pups had decreased liver folate activity compared to controls. Milk free folate activity was significantly decreased by 34% in iron-deficient dams compared to controls. To determine if iron deficiency affected folate status at birth, experiment 2 was conducted. Nine pregnant rats (215-230 g) were fed one of two diets (6 ppm Fe, 1 ppm folate or 250 ppm Fe, 1 ppm folate) throughout gestation and until day 2 of lactation. Liver and kidney folate activities were similar in both groups of pups on day 2 of lactation. It is concluded that the stress of lactation superimposed on iron deficiency alters the folate composition of rat milk, and results in folate depletion in 18-day-old rat pups.