[Li, Min; Yang, Lichen; Mao, Deqian; Shan, Xiaoyun] Natl Hlth Commiss Peoples Republ China, Chinese Ctr Dis Control & Prevent, Natl Inst Nutr & Hlth, Key Lab Trace Element Nutr, 29 Nanwei Rd, Beijing 100050, Peoples R China.
[Shan, Xiaoyun] Univ South China, Sch Publ Hlth, 28 Changsheng West Rd, Hengyang 421001, Peoples R China.
[Liu, Changqing; Luo, Xiaoyan] Hebei Prov Ctr Dis Control & Prevent, Shijiazhuang 050011, Hebei, Peoples R China.
[Zou, Yan; Huang, Lichun] Zhejiang Prov Ctr Dis Prevent & Control, 3399 Binsheng Rd, Hangzhou 310051, Peoples R China.
[Zhou, Weiwen; Qin, Qiulan] Guangxi Ctr Dis Prevent & Control, 18 Jinzhou Rd, Nanning 530028, Peoples R China.