b12 injection take effect Vitamin Side Effects and Safety What Are B12 Shots? 5

Its essentially a fast-acting hydration solution that replenishes all the fluids you need to ward off infections and boost your energy as well as making your blood cells work properly, carrying oxygen around the body and boosting your energy and mood and relieving symptoms of fatigue

Intravenous Administration The way B12 injections are given, either intramuscularly or intravenously, affects how well they work

There may have been other things in the mix such as Iron etc, but its highly unlikely there's a B6 toxicity issue

As a note, this is the recommended dietary allowance (RDA), which is often the bare minimum of a nutrient necessary for function