The effect of oral contraceptive agents on copper and zinc balance in young women

An 18-day balance study was designed to test the hypothesis that the use of oral contraceptive agents would change the metabolic balance of copper and zinc in young women. The subjects were divided into two treatment groups based on the use or non-use of oral contraceptive agents, The mean age was 21 years and 6 months for the non-oral contraceptive group and 21 years and 2 months for the oral contraceptive group. The mean weight was 57.2 kg for the non-oral contraceptive group and 59.7 kg for the group on oral contraceptive therapy. The study was composed of three 6-day periods. The subjects of both groups consumed identical diets for the three experimental periods. The diet contained approximately 2 mg of copper, 9 mg of zinc, 50 g of protein, 181 mg of cholesterol, and 2000 kcal per day. The first experimental period served as an adjustment period with the latter two periods serving as the balance periods. Subjects were given a multi-vitamin supplement daily. All urine and feces were collected and assayed for copper, zinc, and nitrogen. Food samples were measured for content of copper, zinc, and nitrogen. Blood samples were taken and the plasma fraction analyzed for copper, zinc, and cholesterol content. Urinary copper was measured as an organic chelate by atomic absorption spectrophotometry. Copper and zinc content of the other samples were assayed in wet ashed samples by atomic absorption spectrophotometry. Food and fecal nitrogen was assayed by Kjeldahl analysis. Urine nitrogen and creatinine was measured by standard automated techniques. No significant differences were found in the metabolic balances of copper, zinc, and nitrogen. Oral contraceptive users were found to have significantly (p