A vitamin B12 injection is a shot that delivers B12 directly into your muscle, helping your body absorb it quickly (especially if your body struggles to absorb it from food or tablets) Vitamin Shots in Gilbert, Chandler, & Mesa, AZ DrSkin Med Spa & Plastic Surgery Vitamin B 12 intramuscular injections are also used therapeutically to help restore energy and combat various symptoms related to such deficiencies. Vitamin B 12 is essential to the development of healthy blood cells, nerve 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 )