The purpose of this pilot study to examine the feasibility and acceptability of paricalcitol in adults with Chronic Pancreatitis (CP).

Examine the feasibility of a trial to test the effect of paricalcitol through health-related quality of life, imaging, and biomarker analysis in patients with chronic pancreatitis (CP). The study hopes the proposed intervention will improve symptoms based on preclinical evidence that vitamin D analogues have significant and beneficial effects on pancreatitis cancer by blocking certain signaling proteins to reduce pain.

Medical history, concomitant medications, and laboratory test results will be reviewed at all visits by one of the study physicians. In addition, at the beginning and end of the study period, patients will have an MRI to assess condition and DEXA scan to measure bone mineral density, to compare and determine if those receiving paricalcitol have a clinically significant decrease in bone mineral density compared to those receiving placebo for safety. In addition to scans, routine labs will be obtained to assess for any adverse events or safety concerns. Mechanistic specimens for research purposes will be collected at each of the following in person visits: Screening/Randomization, Month 6, Month 12.

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 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