IFNA1 and hypercalcemia disease: None of the patients showed side effects from 1(OH) vitamin D3 administration such as hypercalcemia or renal dysfunction, etc. The rate of the sustained virological response (SVR) in the overall patients treated with 1(OH) vitamin D3/Peg-IFN/RBV was 59.45% (45.24% in the overall patients treated with Peg-IFN/RBV) (p = 0.2059) The rate of SVR in the IL28B (T/T) patients treated with 1(OH) vitamin D3/Peg-IFN/RBV was 73.07% (55.17% in IL28B (T/T) patients treated with Peg-IFN/RBV) (p = 0.1657).