1. WHO Collaborating Center for Reproductive Health and Population Science, Beijing, P. R. China
2. Institute of Population, Peking University, Beijing, P. R. China
3. Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, P. R. China
4. David H Murdock Research Institute, North Carolina Research Campus, Kannapolis, North Carolina, United States
5. Capital Institute of Pediatrics, Beijing, P. R. China
6. Reproductive and Genetic Center of National Research Institute for Family Planning, Beijing, P. R. China
7. Department of Nutrition, University of North Carolina at Greensboro/The UNCG Center for Research Excellence in Bioactive Food Components, North Carolina Research Campus, Kannapolis, North Carolina, United States
8. School of Pharmacy, Shanghai Jiao Tong University, Shanghai, P. R. China