Vitamin B12 Injections Specialist in Langhorne, PA How Quickly Does a B12 Injection Work? Timeline and Expectations Bolt Pharmacy Experiencing any of these symptoms? B12 supplementation might be right for you. Some causes of low B12 are diet, alcohol use, certain diseases like Chrohn's and Celiac Disease, and Gastric Bypass surgery, Vitamin B12 deficiency, sometimes called cobalamin deficiency, happens when your body is either not getting enough or not absorbing enough vitamin B12 from the foods you eat. Vitamin B12 is an important Vitamin B12 Deficiency: A Fact Sheet on Signs, Treatment and Benefits B12 Shots: Vitamin B12 Injections Benefits, Uses, Risks Dr. Axe