Vitamin B12 shots, microneedling, ear candling do any of these at home medical treatments work? 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 B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics B12 Shots & B12 Injections: The Good, Bad and Alternative!