Benefits of B12 Injections for Optimal Health When Should You Get a Vitamin B12 Injection? Soza Clinic 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 Are Vitamin B12 Shots Right for You? B12 Injection Frequency: How Often Should You Get a B12 Shot? Liv Hospital