Benefits of a Vitamin B12 Injection, Vitamin B12 injections are commonly used for people who are deficient, struggle to absorb B12 from tablets, or require a faster and more effective boost., Helps Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta analysis Irish Journal of Medical Science (1971 ) B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics B12 Injections: Are they more effective than supplements? Vivo Life Vivo Life EU Benefits of a Vitamin B12 Injection Vitamin B12 injections are commonly used for people who are deficient, struggle to absorb B12 from tablets, or require a faster and more effective boost.