Causes of Vitamin B12 Deficiency - Cobalamin Decreased Intake Pancreas: Insufficiency Intestine: SIBO, Celiac disease, IBD, Lymphoma, Amyloidosis, Resection, D. latum Stomach: Pernicious anemia, Bypass/gastrectomy, H. pylori infection, B12 malabsorption, Gastritis Other: Medications (PPI, H2 blockers, metformin), Genetic - BWH Medicine Chiefs @BrighamChiefs #Vitamin #B12 #Deficiency #Cobalamin #differential #diagnosis #causes