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 B12 Injection Unlimited Health and Wellness B12 INJECTIONS Vitamin B12 is a nutrient that helps keep the body's nerve and blood cells healthy and helps make DNA, the genetic material in all cells. Vitamin B12 also helps Vitamin B12 Deficiency: Symptoms, Causes & Treatment B 12 Shots at Neighborhood Medical Center in Dallas, TX