VTechWorks staff will be away for the winter holidays starting Tuesday, December 24, 2024, through Wednesday, January 1, 2025, and will not be replying to requests during this time. Thank you for your patience, and happy holidays!

Browsing by Author "Bowen, Phyllis E."

Now showing 1 - 2 of 2
  • Thumbnail Image
    The effect of oral contraceptive agents on copper and zinc balance in young women
    Crews, Michael Glen (Virginia Tech, 1978-08-15)
    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<0.01) higher plasma cholesterol and copper levels, but plasma zinc concentrations were not significantly different. No difference was found in hemoglobin or hematocrit for the two groups. The urinary excretion of zinc was similar for the two groups. The excretion of copper and creatinine was significantly (p<0.01) higher for the oral contraceptive group. The urinary and fecal excretion of copper and zinc was not significantly different for the two groups. While the balance data was not different for the two groups, it is of interest that both groups maintained negative balance states on intakes similar to projected intakes for the general population. This indicated that both groups needed more copper and zinc than they received, It therefore appears that consideration should be given to a possible suboptimal nutritional state existing for copper and zinc nutrition for at least this sex-age group.
  • Thumbnail Image
    Relationship between zinc and copper nutritional status and risk factors associated with cardiovascular disease
    Geders, Jane M. (Virginia Tech, 1978-08-15)
    A study was conducted to assess the relationship between the zinc/copper ratio and risk factors (hypertension, obesity, elevated serum cholesterol and triglycerides, cigarette smoking, and exercise activity level) associated with susceptibility to cardiovascular disease. A questionnaire technique for assessment of physical activity was presented. The zinc/copper ratio was determined from the zinc and copper concentrations of hair samples obtained from sixty-four male subjects, ranging in age from 19 to 59 years. Correlation coefficients revealed no discernible relationship between either the zinc and copper content of hair, or the zinc/copper ratio obtained from these values. Serum cholesterol and triglyceride values, zinc concentrations in hair and the zinc/copper ratio were tested for significant differences associated with age. Statistical analysis indicated that these parameters were not significantly different. Such results were attributed to the wide range of variation within groups for this sample population. Data was not supportive of Klevay's altered zinc/copper ratio hypothesis as the major factor in the etiology of cardiovascular disease.