The purpose of this study is to determine the amount of zinc our bodies absorb and require from food.

• Healthy women between the ages of 21 to 51
• No prescribed medications other than birth control pills or hormone replacement therapy
• Have not been pregnant in the last year and not currently breast feeding. Pregnant women are not eligible for this study
• Have not taken zinc supplements and/or highly fortified food products (foods providing 100% of the RDA for several nutrients) exceeding a total of 20 mg of zinc per day for 6 months and willing to discontinue all nutrient supplements and/or highly fortified food products as soon as your application is accepted
• No rigorous physical training
• Open to smokers

The study will last for 16 weeks, and for 8 weeks and 6 days, you will eat meals and drink beverages provided by the Center. Most of the food ingredients come from a local grocery store. Each diet will follow a 2-day repeating menu.

During the controlled diet period, you will be expected to come to the Center every week day, except holidays, for breakfast. This means you will be limited in the distance you can go from the Center during the week. You could leave the area after eating your breakfast on Friday, as long as you were back for Monday breakfast. If you leave, you will be expected to take your food with you and make arrangements for refrigeration and cooking.

We will measure zinc absorption from the diet through a trace amount of radioactive zinc added to the foods for two days at week 0 and another two days at week 12. You will have whole body counts to detect radiation in the body and have blood drawn.