Oral vs. Intramuscular Vitamin B12 in Vitamin B12 Deficiency The Blood Project Tirzepatide Oral vs Injection: Pros, Cons & Side Effects When would sublingual B12 supplements (as opposed to B12 tablets or injections) be indicated in a client with B12 deficiency? , The choice to use a sublingual B12 versus a tablet or injection is PDF) Comparison of sublingual vs. intramuscular administration of vitamin B12 for the treatment of patients with vitamin B12 deficiency