Too Much Vitamin B12: Risks, Symptoms and When to Seek Help Bolt Pharmacy B12 Shots & B12 Injections: The Good, Bad and Alternative! Vitamin B12 Injection Dosage for Adults: 7 Key Medical Guidelines Liv Hospital 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 Quickly Does B12 Shot Work? Does It Help to Lose Weight?