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 Does size matter? Historically, a bigger needle gauge was considered better to prevent damage to red blood cells. However, our recent guidelines recommend using smaller gauge needles (2325 G) for all Vitamin B12 Injections: Hot Shots? Full Guide PA Relief Medical needle hi res stock photography and images Page 20 Alamy a disposable syringe with a needle and an ampoule with red (vitamin B12) liquid in male hands in blue (lilac) nitrile gloves. On a white background Stock Photo Alamy