All consenting participants will be randomized into the vitamin D treatment group or the control group, general information and baseline biochemistry data would be collected. Patients in the treatment group will be treated with oral Cholecalciferol (2000IU/day) apart from routine treatment for PD. Those in the control group will receive routine treatment for PD. Both groups will be followed for 24 months. During the observational period, any onset of subsequent peritonitis will be recorded, serum 25(OH)D, biochemical indices will be measured every 3 months. Follow up would take place frequently, any outcome events would be recorded.