Vitamin B12 injections deliver high doses of this essential vitamin directly into your bloodstream for better absorption than oral supplements to boost energy, support red blood cell production and maintain nerve function. Vitamin B12 injections deliver high doses of this essential vitamin directly into your bloodstream for better absorption than oral supplements to boost energy, support red blood cell production and maintain nerve function. Benefits of B12 Injections for Optimal Health The B12 Shot: What Every Human Needs to Know About Injectable Vitamin B12 B12 Injections for Energy: Benefits and How It Works AZ IV Medics