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, What are the benefits of B12 injection? Blades Wellness Why Do I Feel Worse After My B12 Injection? Understanding Post Injecti Oxford Origins How Quickly Does a B12 Injection Work? Timeline and Expectations Bolt Pharmacy B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Some Types Of Vitamin B12 Supplements Can Cause This Side Effect