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 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 Vitamin B12 Trio Vit B12 INJECTIONS vs B12 Tablets ? Name Dose & Duration of B12 Tablets Dr Rupal Explains B12 Shots & B12 Injections: The Good, Bad and Alternative!