Optimal Vitamin B12 Dosage and Treating Deficiency Main benefits of B12 injections 1) Increased energy & reduced fatigue B12 helps convert food into usable energy Deficiency often causes tiredness, weakness, and low stamina 2) Healthy red blood cells Prevents B12 Injections at Home Safety Guide for Self Administration Infusion For Health B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics