Abstract: 【Abstract】Objective To explore the mediator effect of vitamin D between physical activity and quality of life in patients undergoing hemodialysis. Methods Physical activity and quality of life in the 94 maintenance hemodialysis patients were measured by the International Physical Activity Questionnaire of Long Version and Brief Health Status Scale. Serum 25(OH)D3 was also measured. Results Both the direct effect of physical activity (logarithm) on physical component summary [C’=7.785 (5.804, 9.766), P<0.001] and the indirect effect through serum 25(OH)D3 [ab=0.452(0.017,1.203)] were significant. Conclusion Vitamin D played as a mediator between physical activity and quality of life. Higher serum 25(OH)D3 level may help improve quality of life in hemodialysis patients.

Key words: Maintenance hemodialysis, Physical activity, Vitamin D, Quality of life