Vitamin D + Telaprevir + Peginterferon + Ribavirin for of Hepatitis C Genotype 1

This study is for people who have been diagnosed with chronic hepatitis C, specifically those who have a certain type of the virus, genotype 1, and who have not yet received treatment for hepatitis C. This pilot study is designed to test whether the addition of vitamin D, to the three drugs (Incivek (telaprevir), Pegasys (peginterferon alfa-2a), and ribavirin) that are approved by the Food and Drug Administration (FDA) for the treatment of hepatitis C, can help eliminate the HCV from the body. Currently, doctors are unsure if the addition of vitamin D to prescribed hepatitis C therapy will have any effects on how the body clears the virus. Once enrolled, participants will be randomly assigned (like flipping a coin) to receive telaprevir + peginterferon alfa-2a + ribavirin + vitamin D3 (treatment group) or telaprevir + peginterferon alfa-2a + ribavirin (control group). A total of 80 participants, of all races/ethnicities, will be included in this study, at 5 to 10 VA hospital study sites (10 - 20 participants/site). Participants assigned to the treatment group will begin a lead-in phase where they will receive 5,000 IU of vitamin D3 per day. Every two weeks during the lead-in phase, participants will be tested to determine the Vitamin D level in their blood, as well as other tests, including HCV RNA (to determine the amount of virus present) and calcium levels. Once an adequate level of Vitamin D is detected in participants' blood, participants will begin treatment with telaprevir + peginterferon alfa-2a + ribavirin + vitamin D3 (15,000 IU/week) for 12 weeks. Participants randomized to the control group will immediately begin treatment with telaprevir + peginterferon alfa-2a + ribavirin for 12 weeks. At the end of Week 12 the participants' involvement in the study will be complete. Adverse events and effects of vitamin D3 will be obtained by assessing participants' medical history, physical examination, and blood tests at clinic visits. HCV RNA will be assessed a