Effects of maternal iron nutrition during lactation on milk iron and rat neonatal iron status.

We studied the milk iron content and iron status of lactating rats and their pups to investigate the relationships between the iron concentrations of maternal diet and the iron content of milk, and that between the milk iron content and neonatal iron status. Three days after parturition lactating rats were divided into three groups and fed a control (250 ppm iron), a high iron (2500 ppm iron), and an iron-deficient (no iron) diet. During lactation pups and dams from each group were killed periodically and iron status determined by measurements of hemoglobin, plasma iron, total iron binding capacity, and ferritin. Milk iron concentration decreased in all diet groups during lactation. The rate of decrease was diet dependent. A definite relationship was seen between the milk iron content of dams and the iron status of their pups. The iron concentration of rat diet was also found to influence the maternal iron during lactation.