Vitamin C (also called L-ascorbic acid or ascorbate) is a nutrient that humans must get from food or dietary supplements since it cannot be made in the body. Vitamin C is an antioxidant and helps prevent oxidative stress. It also works with enzymes to play a key role in making collagen. When taken by intravenous (IV) infusion, Vitamin C can reach much higher levels in the blood than when it is taken by mouth. Studies suggest that these higher levels of Vitamin C may cause the death of cancer cells in the laboratory. A high dosage of Vitamin C has been touted as an effective alternative treatment to chemotherapy for cancer.