What needle size is best for injec Pernicious Anaemi Treating Severe Vitamin B12 Deficiency B12 IM Injection How to Give a B12 Injection: Step By Step Instructions Not all shots are the same here's a guide Injections are a fast, effective way to deliver medications, nutrients, and vaccines directly into the bodybut not all injections are the Dr. prescribed B12 injections. Pharmacy only gave me vials. Where do you get your needles and syringes? What size?? Where do I inject? : r B12_Deficiency Vitamin B12 Injections