Best Vitamin B12 Injection Sites: Where to Inject B12 PA Relief B12 Shots for Weight Loss: What You Need to Know ISSA How Often Should I Get B12 Shots? A Guide to Your Schedule Vitamin B12 Overdose: How Much Is Too Much? Dr. Axe 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