Vitamin B12 deficiency
Vitamin B12, or cobalamin, is a water-soluble vitamin found in meat, fish, and dairy products and, once combined with intrinsic factor in the stomach, is absorbed in the ileum. Patients at risk for vitamin B12 deficiency include those with a lack of intrinsic factor (pernicious anemia) or antibodies to intrinsic factor, malabsorption syndromes (especially those who have had a gastrectomy, gastric bypass, or chronic pancreatitis), or infections such as Helicobacter pylori or tapeworm infections. In addition, strict vegans, older adults, and people with alcohol use disorder are particularly vulnerable to vitamin B12 deficiency. Elderly patients are at risk due to the high prevalence of atrophic gastritis. Patients with autoimmune conditions such as Graves disease, thyroiditis, and vitiligo are also at risk.
E53.8 – Deficiency of other specified B group vitamins
190634004 – Cobalamin deficiency
Differential Diagnosis & Pitfalls
Drug Reaction Data