Vitamin C has many important functions in the body, including its role as an antioxidant. The body cannot make or store vitamin C. It has to be obtained from the diet and supplements. It is well accepted that vitamin C is an essential micronutrient. However, its use in megadose quantities remains controversial, as does the use of high-dose vitamin C in cancer treatment.
What is vitamin C infusion therapy?
Vitamin C can be taken by mouth (orally) or given by intravenous infusion directly into the bloodstream. When it is given intravenously, much higher blood levels of vitamin C are reached compared to when it is ingested by mouth.
How much is a megadose of vitamin C?
Any dose above 1 gram of vitamin C per day is considered a megadose quantity.1
Can IV Vitamin C cure cancer?
Experiments with vitamin C for cancer treatment date back several decades. The well-known Scottish surgeon Ewan Cameron and two-time Nobel-laureate Linus Pauling treated 100 terminally ill cancer patients with vitamin C in the 1970s. They compared these patients to controls who were treated at the same hospital for a similar type of cancer and clinical stage but did not receive vitamin C. The results showed that the patients treated with vitamin C had a four times higher average survival time. A follow-up study found that 22 percent of cancer patients treated with vitamin C survived one year compared to 0.4 percent of those who did not receive the treatment.1
Subsequently, the Mayo Clinic conducted randomized double-blind trials on the use of vitamin C in cancer patients. These trials failed to demonstrate any positive effects of high-dose vitamin C in cancer patients. However, the Mayo Clinic trials consisted of vitamin C treatment for an average of 2.5 months, whereas the Pauling-Cameron study lasted for 12 years. Also, the Mayo Clinic study consisted of 10 grams of vitamin C by mouth. The Pauling-Cameron trial administered vitamin C both orally and intravenously, producing 25 times higher peak plasma concentrations. This suggests that intravenous administration of vitamin C can achieve and sustain high plasma levels that are sufficient to kill cancer cells.1
It remains controversial whether high-dose intravenous vitamin C alone can cure cancer. However, experts agree that vitamin C can boost the effectiveness of conventional cancer treatments like chemotherapy and radiation therapy.2
Can Vitamin C prevent cancer?
Scientists at the Johns Hopkins University have shown vitamin C and other antioxidants can prevent the growth of some tumors.3 Other studies have found that daily vitamin C supplementation can reduce the incidence of many types of cancer, including oral, pharyngeal, esophageal, gastric, and cervical cancers. Vitamin C rich foods are thought to prevent lung and colon cancers.4 However, large-scale trials have not demonstrated that vitamin C supplements can prevent cancers.5
How does vitamin C kill cancer cells?
Certain molecules called oxygen free radicals are known carcinogens, i.e., they cause cell damage and stimulate the development of cancer.6 Vitamin C is an antioxidant that prevents cancer growth by grabbing up these free radicals. Vitamin C does not allow free radicals to damage the DNA in cells.2 Scientists have also found that antioxidants like vitamin C destabilize tumor cells and prevent them from growing.3
Vitamin C cancer treatment
At present, the US FDA has not approved the use of high-dose intravenous vitamin C for cancer treatment. Scientists are still investigating whether intravenous megadose quantities of vitamin C can prevent and cure cancer. Nonetheless, many studies have shown that cancer patients who receive IV vitamin C have a better quality of life and fewer side effects from cancer treatments.7 Doses of vitamin C up to 1.5 grams/kilogram of body weight is considered safe in most patients with very few side effects.