How to Give a B12 Injection: Step By Step Instructions How Often Are B12 Injections Given B12 Injection Frequency: How Often Should You Get a B12 Shot? Liv Hospital How to Give a B12 Injection: Step By Step Instructions How often should vitamin B12 injections be administered and how frequently should laboratory monitoring be performed? 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