Director of Endocrinology, Professor, Chief Physician, and Doctoral Supervisor at Peking Union Medical College Hospital, Chinese Academy of Medical Sciences. Dr. Xia specializes in endocrine and metabolic disorders, with profound expertise in the basic and clinical research of metabolic bone diseases. He has rich clinical experience in diagnosing and treating common endocrine and metabolic diseases such as diabetes, hyperthyroidism, metabolic syndrome, hypothalamic-pituitary diseases, adrenal diseases, and gonadal diseases. He served as a visiting scholar at the University of Tokyo, Japan, from 2000 to 2001. His current research focuses on the genetic pathogenesis of endocrine and metabolic diseases, the epidemiology of osteoporosis and fractures, and basic and clinical research on rickets and osteomalacia. He has led multiple national research projects, including those funded by the National Natural Science Foundation of China, and has published over 80 scientific papers. He also serves as an editorial board member and editorial director for the 'Chinese Journal of Osteoporosis and Bone Mineral Research'.