How Often Can You Get a B12 Shot for Maximum Health? What are Vitamin B12 injections Vitamin B12 injections are used to quickly raise your B12 levels when they're low or when your body can't absorb it properly from food or tablets. What Vitamin B12 Shots for Ultimate Rejuvenation in Catonsville MD NAD+ & B12 Injections in Crewe, Cheshire How often should vitamin B12 injections be administered and how frequently should laboratory monitoring be performed? How to self inject intramuscular vitamin B12 Overview Guy's and St Thomas' NHS Foundation Trust