Calcitriol, Cisplatin, and Gemcitabine Hydrochloride in Treating Patients With Advanced Solid Tumors That Cannot Be Removed by Surgery

Inclusion Criteria

• •Patients with a diagnosis of advanced unresectable non-hematological malignancy that has no known standard of care or for which the use of gemcitabine plus cisplatin constitutes a reasonable option
• •Have an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1
• •White blood cell (WBC) \>= 3.0 x 10\^9/L
• •Neutrophils \>= 1.5 x 10\^9/L
• •Platelets \>= 100 x 10\^9/L
• •Hemoglobin (Hgb) \>= 10 g/dL
• •Bilirubin =\< institutional upper limit of normal (ULN)
• •Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \< 2.5 x institutional ULN unless metastatic to liver in which case AST and ALT should be \< 5 x institutional ULN
• •Creatinine =\< 1.5 x institutional ULN
• •Corrected calcium =\< institutional ULN (corrected calcium = (4- Albumin) x 0.8 + calcium)
• •Patients of child-bearing potential must agree to use acceptable contraceptive methods (e.g., double barrier) during treatment
• •Patient or legal representative must understand the investigational nature of this study and sign an Independent Ethics Committee/Institutional Review Board approved written informed consent form prior to receiving any study related procedure
• •No treatment with investigational agents within 4 weeks prior to study drug administration, except patients receiving targeted therapies such as kinase inhibitors with half-lives \< 48 hours may be treated if \> 14 days have elapsed after the last dose and related toxicities have recovered to =\< grade 1
• •No chemotherapy within 4 weeks prior to study treatment administration; nitrosoureas and mitomycin C are not allowed within 6 weeks prior to initiation of study treatment
• •Palliative radiation, including whole brain radiation therapy (WBRT), is allowed prior to enrollment as long as it is completed \> 2 weeks from initiation of study treatment, and provided patient has recovered from treatment toxicities to =\< grade 1
• •Patients should be able to take oral medications