Boost Your Energy and Mood with a Fast, Safe B12 Shot in Santa Barbara MiraMed and Day Spa How Often Will I Need Vitamin B Complex Injections? How often should vitamin B12 injections be administered and how frequently should laboratory monitoring be performed? 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