B12 Injections for Energy: Benefits and How It Works AZ IV Medics Vitamin B12 Injections: What You Need To Know Methylcobalamin Injection Dosage Frequency Neuropathy Optimal B12 Injection Sites for Maximum Absorption and Benefits Your Health Magazine 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.