D51.1 - Vitamin B12 deficiency anemia due to selective vitamin B12 malabsorption with intrinsic factor deficiency: Applied when macrocytic anemia results from selective vitamin B12 malabsorption with intrinsic factor deficiency, affecting vitamin B12 absorption
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Last reviewed January 2026
There is no accumulation concern with either formulation at standard injectable doses
[51] Diagnosis [edit] According to one review: "At present, no 'gold standard' test exists for the diagnosis of vitamin B 12 deficiency and as a consequence the diagnosis requires consideration of both the clinical state of the patient and the results of investigations." [52] The vitamin deficiency is typically suspected when a routine complete blood count shows anemia with an elevated mean corpuscular volume (MCV)
Best Time to Take B12 for Weight Loss: Evidence and Guidance Vitamin B12 (cobalamin) is an essential water-soluble vitamin vital for red blood cell formation, neurological function, and energy metabolism
