A PiLot ClinicaL TrIal of ParicAlcitol for ChroNiC PancrEatitis (ALLIANCE)

Inclusion Criteria: Provision of signed and dated informed consent form Stated willingness to comply with all study procedures and availability for the duration of the study Male or female, aged 18-75 at time of enrollment Diagnosis of Chronic Pancreatitis episode is not attributable to gallstones (i.e. suspected or definite biliary etiology), medications, trauma or autoimmune pancreatitis. Ability to take oral medication and be willing to adhere to the dosing regimen Normal Calcium levels- 8.5 to 10.2 mg/dL Normal Phosphate levels- 2.8 to 4.5 mg/dL Normal Parathyroid hormone levels- 10 to 65 pg/mL For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation and for an additional 1 week after the end of Investigational Product administration For males of reproductive potential: use of condoms or other methods to ensure effective contraception with partner No prior pancreatic surgery Pancreatic necrosis, if present, is <50% (to be verified by a CPDPC site radiologist) No involvement in any interventional trials currently or within 6 months of enrollment Exclusion Criteria: Pregnancy or lactation History of autoimmune or traumatic pancreatitis, or sentinel attack of acute necrotizing pancreatitis which results in suspected disconnected duct syndrome Primary pancreatic tumors - pancreatic ductal adenocarcinoma, suspected cystic neoplasm (>1 cms in size or main duct involvement), neuroendocrine tumors, and other uncommon tumors. Pancreatic metastasis from other malignancies History of solid organ transplant, HIV/AIDS. Abnormal lab values: calcium, phosphate, or parathyroid hormone Known isolated pancreatic exocrine insufficiency (e.g. in the absence of any eligible inclusion criteria) Participants must not have medical or psychiatric illnesses or ongoing substance abuse that in the investigator's opinion would compromise their ability to tolerate study interventions or participate in longitudinal follow up Patients with known abnormal creatinine (GFR < 30) or renal failure (applies to patients with chronic upper abdominal pain of suspected pancreatic origin and suspected CP. Known Pregnancy. All participants of childbearing potential, except if post-menopausal [i.e. no menses for ≥2 years] or had a hysterectomy, bilateral tubal ligation/clip (surgical sterilization) or surgical removal of both the ovaries), must have a negative urine or serum B-HCG pregnancy test documented within 2 days prior to any endoscopic or radiologic procedures done for research purposes. Any standard of care tests will follow institutional policies regarding pregnancy test Currently incarcerated Inability to tolerate MRI