They are not for human consumption, medical, or veterinary use
Conclusion All IM, oral, and SL routes of administration of vitamin B12 can effectively increase the level of vitamin B12 without significant differences between them, as thought previously
Goon PK, Lip GY, Boos CJ, Stonelake PS, Blann AD
Further guidance on assessment and management of B12 deficiency is available via NICE Clinical Knowledge Summary (CKS): Anaemia B12 and folate deficiency
Conversely, vitamin B12 injection allergies can be attributed to various components other than the vitamin itself, with reactions potentially resulting from additives like benzyl alcohol and preservatives such as aluminum and phenylcarbinol, as well as potential inactive ingredients which can vary depending on factors, such as the formulation and brand of the vitamin B12 injection