Most of us are familiar with oral vitamin supplements. They come in a pill or a capsule and you take one or two a day as directed. These are great for slowly increasing specific nutrients you may not be getting from your diet.
IV (Intravenous) nutrient therapy is a completely different way to get therapeutic levels of a given nutrient directly into the blood stream to create therapeutic change. Oral nutrient supplementation can only be absorbed so much once the digestive process get a hold of the vitamin. IV therapy completely bypasses the digestive system.