From the Guidelines
High-dose intravenous vitamin C (IVC) therapy for cancer is not currently recommended as a standalone treatment for any type of cancer. While some studies suggest potential benefits, the evidence remains insufficient to support its routine use outside of clinical trials 1. Typical protocols involve doses ranging from 0.4g/kg to 1.5g/kg body weight administered 1-3 times weekly, with some protocols using up to 75-100g per infusion. These treatments must be administered by healthcare professionals in appropriate medical settings due to potential side effects including nausea, dizziness, and risk of kidney stones.
Key Considerations
- Patients with G6PD deficiency, kidney disease, or certain hemochromatosis conditions should avoid this therapy.
- The proposed mechanism involves vitamin C generating hydrogen peroxide, which may selectively damage cancer cells while sparing normal cells, and potentially enhancing chemotherapy effects.
- However, IVC should only be considered as a complementary approach alongside conventional cancer treatments, not as an alternative.
- Patients interested in this therapy should discuss it with their oncologist to evaluate potential benefits and risks based on their specific cancer type and overall health condition 1.
Important Notes
- The use of very large doses of vitamins, minerals, and other dietary supplements can cause physical harm.
- The Dietary Reference Intakes provide recommendations of amounts of most vitamins and minerals needed for optimal health as well as the established Upper Tolerable Limits for most healthy persons.
- Identification of upper tolerable limits and toxic effects is important because, for some, the practice of dietary supplementation has moved beyond the goal of health promotion and disease prevention to include speculation that dietary supplements may be instrumental in cancer prevention and treatment.
From the Research
High-Dose Vitamin C IV and Cancer
- High-dose intravenous vitamin C (IVC) has been proposed as a potential therapeutic approach for cancer treatment, with studies suggesting its anti-cancer effects as a pro-oxidative cytotoxic agent, anti-cancer epigenetic regulator, and immune modulator 2, 3.
- The pharmacokinetics of vitamin C differ significantly between oral and intravenous administration, with IV administration allowing for higher plasma concentrations required for anti-tumor effects 3, 4.
- Preclinical evidence suggests that high-dose IVC can tailor treatment in cancer patients, particularly those with specific molecular defects, and may provide a rationale basis for combination therapies with other agents 3.
Mechanisms of Action
- Vitamin C has been shown to have pro-oxidant effects at high concentrations, generating hydrogen peroxide and inducing cell death in cancer cells 2, 4.
- Additionally, vitamin C can modulate TET enzymes, promoting DNA demethylation, and act as a cofactor for HIF hydroxylases, which is required for HIF-1α proteasomal degradation 3.
- Vitamin C may also alter the DNA damage response by increasing 5-hydroxymethylcytosine levels, offering new treatment opportunities for tumors with specific molecular defects 3.
Clinical Evidence
- While early phase clinical trials have confirmed the safety and indicated efficacy of IVC in eradicating tumor cells, strong clinical data and phase III studies are lacking 2.
- Current clinical evidence for a therapeutic effect of high-dose IV vitamin C is ambiguous, and its use cannot be recommended outside of a clinical trial 4.
- However, studies suggest that combining vitamin C with other antioxidants, such as N-acetylcysteine, may enhance its anti-cancer effects and prevent adverse effects 5.
Future Directions
- Further research is needed to fully understand the pharmacodynamic properties of high-dose IVC and its potential role in cancer treatment 2, 3.
- The use of liposomal delivery systems may enhance the bioavailability and anticancer effects of vitamin C, and combination therapies with other agents may provide new treatment opportunities 6.