Very high rates of vitamin D insufficiency in women of child-bearing age living in Beijing and Hong Kong. - Woo J; Lam CW; Leung J; Lau WY; Lau E; Ling X; Xing X; He Zhao X; Murray Skeaff C; Bacon CJ; Rockell JE; Lambert A; et al. (British Journal of Nutrition, 2008)