When Should You Get a Vitamin B12 Injection? Soza Clinic B12 Injections: How Often Should You Take Them? Invigor Medical 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 How Often Will I Need Vitamin B Complex Injections? B12 Injection sites + How to use B12 Shots Safely