Vitamin C in very high doses is capable of reducing tumor resistance to conventional therapies by modulating the aberrant metabolism. Some of the properties of the vitamin can be toxic to cancer cells.

In order for vitamin C to have oxidative activity, which is what is sought in tumor cells, it must be given in very high doses and preferably intravenously; this effect is not usually achieved with oral administration.

High doses of intravenous vitamin C reach the blood directly. It is a great antioxidant, acting in the organism transporting oxygen, hydrogen and having effects against oxidative free radicals that degenerate or worsen cells, helping the progression of cancer.

There are multiple studies that demonstrate the efficacy of ascorbic acid, which is essentially equivalent to vitamin C when administered continuously in protocols.

The administration of intravenous vitamin C in very high doses is considered a very safe and effective treatment to treat cancer patients.