This step-by-step guide will walk you through everything you need to know, from preparing your supplies to administering the injection safely, so you can approach the process with confidence
How we reviewed this article: Current Version October 03, 2025 Written By John DiBella Fact-checked By Dr
Insider's takeaway Vitamin B12 injections are for those with a severe B12 deficiency or conditions that prevent their body from effectively absorbing the vitamin, Moreno says
Others who might be prescribed B12 shots are those at the highest risk for a B12 deficiency, including: Vegans, since vitamin B12 is found only in animal products People ages 60 and up since their bodies don't absorb B12 as efficiently People with Crohn's disease or pancreatic disease, since they prevent nutrient absorption People who had weight-loss surgery, which decreases B12 absorption People with an eating disorder People with HIV People with diabetes Since a mild B12 deficiency might not cause symptoms, it can go undetected for years since levels are not checked during routine blood work
Vitamin B12 injections are an effective way to treat a deficiency, but they're not for everyone
If using a vial : Wipe the rubber stopper with an alcohol swab