Eligible candidates will be adults with metastatic pancreatic cancer (confirmed diagnosis with pathology reports and measurable computed tomography (CT) or magnetic resonance imaging (MRI)). Participants must not be receiving any other concurrent chemotherapy, or radiation therapy. Full inclusion/exclusion criteria are available. History and physical examination, and laboratory and imaging analyses will be done within 14 days prior to registration. The three cohorts of subjects will receive 50, 75 or 100 grams of intravenous ascorbic acid, three times per week for 8 weeks. Subjects will also have co-administration of the chemotherapy medications, gemcitabine (intravenously) and erlotinib (orally). Approximately 9 to 18 participants will be enrolled in this Phase I study.