2 How do you know what is the cause of someones vitamin B12 deficiency
Excessive use of antisecretory medications like omeprazole, proton pump inhibitor, and antimicrobial agent
3.3.1 Central immune system: aberrant activation of microglia and astrocytes In EDC, aberrant microglial and astrocytic activation constitutes a central mechanism linking neuroinflammation to neural circuit dysfunction

INDICATIONS AND USAGE INDICATIONS & USAGE SECTION Cyanocobalamin is indicated for vitamin B12 deficiencies due to malabsorption which may be associated with the following conditions: Addisonian (pernicious) anemia Gastrointestinal pathology, dysfunction, or surgery, including gluten enteropathy or sprue, small bowel bacteria overgrowth, total or partial gastrectomy Fish tapeworm infestation Malignancy of pancreas or bowel Folic acid deficiency It may be possible to treat the underlying disease by surgical correction of anatomic lesions leading to small bowel bacterial overgrowth, expulsion of fish tapeworm, discontinuation of drugs leading to vitamin malabsorption (see Drug Interactions ), use of a gluten-free diet in nontropical sprue, or administration of antibiotics in tropical sprue
The strongest counter is methodological