Many people do but if you have a digestive condition, low stomach acid or any gut absorption issue, very little of an oral supplement will actually be absorbed regardless of the dose
Additional scientific context related to compounds can be found through publicly available research databases such as PubChem
[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)
People with pernicious anemia or people who cannot absorb vitamin B 12 from their intestines will need injections of vitamin B 12 every one to three months indefinitely
Mild, short-lived reactions can include soreness at the injection site, a brief flushing sensation, mild bruising, or, very rarely, mild nausea