Are Vitamin B12 Shots Right for You? 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. B12 Shots & B12 Injections: The Good, Bad and Alternative! Should You Take Natural vs. Synthetic B12? What are Vitamin B12 injections Vitamin B12 injections are used to quickly raise your B12 levels when they're low or when your body can't absorb it properly from food or tablets. What Vitamin Injections Explained: Benefits, Process & Results