How Often Can You Get a B12 Shot for Maximum Health? If you have a low vitamin B12 level, injections can go a long way toward improving your health and well being. But if your B12 level is normal, don't fall for claims that 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 Feeling drained or low on energy? B12 injections can help support: Energy levels Focus Overall wellness A quick and simple way to give your body a boost when