- Decreased stomach acid
- Atrophic gastritis
- Autoimmune pernicious anaemia
- Helicobacter pylori
- Gastrectomy, partial or complete
- Gastric bypass surgery (weight loss)
- Intestinal resection
- Partial or complete ileectomy
- Gastrointestinal neoplasms
- Malnutrition
- Eating disorders - anorexia - bulimia
- Inadequate diet
- Vegetarianism / veganism
- Malabsorption syndromes
- Alcoholism
- Crohn’s disease
- Coeliac disease (gluten enteropathy)
- Dipphyllobothrium infection
- blind loop syndrome
- diverticulosis
- inflammatory bowel disease
- small bowel overgrowth
- tropical sprue
- gastric irradiation
- ileal irradiation (bladder,cervix, uterus,prostate)
- Inborn errors of B12 metabolism
- Transcobalamin II deficiency
- Pancreatic exocrine insufficiency & Chronic pancreatitis
- Imerslund Gräesbeck syndrome
- Zollinger - Ellison Syndrome
- Bacterial overgrowth (small bowel)
- Fish tapeworm
- Advanced liver disease
Drug induced causes - Please note; this list is not exhaustive
- Antacids
- Colchicine (treatment of gout)
- H2 Blockers (Zantac, Tagamet, Pepcid)
- Metformin - Diabetes drug (Glucophage)
- PPI's - Proton pump inhibitors (Omeprazole, Nexium, Prevacid, Protonix)
- Nitrous oxide anaesthesia
- Nitrous oxide recreational abuse (Laughing gas / Whippets / Hippy crack)
- Levodopa (treatment of Parkinson's)
- Mycifradin sulphate (Neomycin) antibiotic
- Para aminosalicylates antibiotic
- Phenytoin (Dilantin) - anti-epileptic
- Potassium chloride (K-Dur)
- Cholestyramine (Questran)
- Chemotherapy and radiation treatment
Increased demands
- Chronic Hemoltic anaemia
- Hyperthroidism
- Multiple myeloma
- Myelopproliferative disorders
- Neoplasms
- Pregnancy
Information provided with kind permission of Sally M. Pacholok R.N. & Dr. Jeffrey J. Stuart.
