Vitamin Injection Stay In Your System Longer Than Tablets Do. Work Istantly And Give The Best Benefits. When taking tablets only 15% stays in your system. The rest is secreted out of B12 vitamin Store Trivit B Complex Uses, Warnings, Cautions and Benefits B12 and B complex vitamins play a major role in how your body produces energy, balances mood, and supports metabolism. When delivered through IV, they bypass the digestive system for faster, more Vitamin B12 Injections Energy Boost The Center Medical