Immune Effects of Vitamin D in Hemodialysis Patients

Inclusion Criteria: * Patient stable on chronic hemodialysis for more than 3 months. * PTH level between 150 - 800 pg/ml. * Ability to give informed consent. * Serum calcium levels (corrected for albumin level of 4.0 g/dL) less than 10.5 mg/dL for the last three consecutive measurements. * Serum Phosphorus levels between 2.5 and 7.0 mg/dL for the last three consecutive measurements. * Ca x P-Product of less than 75 mg2/dL2 in the last three consecutive measurements. Exclusion Criteria: * Known active malignancy. * Liver disease defined as serum aspartate aminotransferase, alanine aminotransferase, or gamma-glutamyltransferase levels more than 2 times the upper limits of normal. * PTH levels between 150 pg/mL and 800 pg/mL. * Hypercalcemia or hypercalcemic episodes within the last 4 weeks. * Ca x P-Product more than 75 mg2/dL2 within the last 4 weeks. * Any clinical significant infections which are or have been treated with antibiotics within 6 weeks prior to start of the study. * Chronic viral infection (HIV, Hepatitis B or C). * Currently on immunosuppressive medication (steroids, cyclosporine, etc…). * Hematocrit less than 30 %. * History of blood disorders other than renal anemia. * Age of less than 18 years or more than 75 years. * Hypersensitivity to paricalcitol or any ingredient of the product. * Parathyroidectomy. * Participation in another study at the same time.