Vitamin Shots in Gilbert, Chandler, & Mesa, AZ DrSkin Med Spa & Plastic Surgery B12 Injections vs Tablets: What You Need to Know Vitamin B12 injections deliver high doses of this essential vitamin directly into your bloodstream for better absorption than oral supplements to boost energy, support red blood cell production and maintain nerve function. The 5 best vitamin B12 supplements for 2026, according to dietitians