Serum vitamin C levels and risk of non-alcoholic fatty liver disease: results from a cross-sectional study and Mendelian randomization analysis oleh Hui Wu, Jiang-Long Guo, Jiang-Long Guo, Jing-Jiong Yao, Jing-Jiong Yao, Jia-Jun Yu, Jia-Jun Yu, Run-Yu Xia, Run-Yu Xia, Wei-Qing Huang, Wei-Qing Huang, Xuan Tang, Xuan Tang, Guang-Ming He