1. Division of Reproductive Health, National Centers for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, 4770 Buford Hwy. NE, Mailstop K-22, Atlanta, GA 30341-3724; phone: 770-488-5227; fax: 770-488-5628;
2. Departments of Nutrition and Maternal and Child Health at the University of North Carolina at Chapel Hill-School of Public Health
3. Department of Nutrition at the University of North Carolina