Efficacy and Safety Study of Oral Eligen® B12 in Subjects With Low Serum Cobalamin

Inclusion Criteria: * Vitamin B12 deficiency defined as serum cobalamin below 350 pg/mL * Age 60 or older; or age 18 or older with gastrointestinal abnormalities including but not limited to gastrointestinal surgery (e.g. gastrectomy, gastric bypass), ileal resection, gastric atrophy, Celiac disease, Crohn's disease, or prolonged use (\>3 months) of proton pump inhibitor drugs, or on a restricted diet (such as vegetarian or vegan). * General good health, as indicated by lack of significant findings in medical history, physical examination, clinical laboratory tests (chemistry, hematology and urinalysis), vital signs, ECG and normal kidney function as determined by estimated creatinine clearance computed with the Cockcroft and Gault formula Exclusion Criteria: * Current treatment from a health care provider to treat vitamin B12 deficiency and/or symptoms; * Daily use of neutralizing antacids (e.g. Maalox®) * Inability to ingest oral medication * Clinically significant laboratory value at screening * Hypersensitivity or allergic reaction to vitamin B12 * Participation in a clinical research study involving a new chemical entity within 30 days of the first study dose * Folate levels below the reference range provided by the clinical laboratory. * Renal insufficiency * Vitamin B6 deficiency