B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Vitamin B12 (cobalamin) and folate (vitamin B9) are vitamins that serve important functions in the human body. Folate is needed for development and growth of cells (including red blood cells) and synthesis How Often Should I Get B12 Shots? A Guide to Your Schedule B12 Shots: Vitamin B12 Injections Benefits, Uses, Risks Dr. Axe Vitamin B12 Overdose: How Much Is Too Much? Dr. Axe