Absorption of stable isotopes of iron, copper, and zinc during oral contraceptives use.

The absorption of iron, copper, and zinc was determined in 22 women 19 to 25 years of age from the difference between intake and fecal output of the stable isotopes 58Fe, 65Cu, and 70Zn, as measured by neutron activation analysis. Of the 22 women, 14 were using oral contraceptive agents, and the other eight were not. Absorption in the group using oral contraceptive agents did not differ significantly from the group not using oral contraceptive agents. The overall iron absorption averaged 14%, copper 57%, and zinc 38%.