Intravenous (I.V.) therapy and injection (intramuscular, subcutaneous) of vitamins and minerals are a safe and effective way to deliver nutrients in a timely and efficient manner. Also known as “parenteral therapy”, substances administered by IV or injection are directly absorbed into the circulatory system, bypassing the “enteric system” or gastrointestinal tract and liver, permitting the highest level of nutrient absorption (near or at 100%).