High-Dose Vitamin C (IV & Oral)
High-dose intravenous Vitamin C (25–100 g) achieves plasma concentrations 100–500x higher than oral supplementation — concentrations shown to selectively kill cancer cells via hydrogen peroxide generation in tumour microenvironment while leaving normal cells unharmed. Multiple phase I/II clinical trials confirm safety and show tumour reduction in pancreatic, ovarian, and glioblastoma cancers. Used alongside conventional chemotherapy, IV-C has shown synergy and reduced treatment toxicity.
Mechanism of Action
At pharmacological (IV) doses, Vitamin C acts as a pro-oxidant — generating hydrogen peroxide (H₂O₂) preferentially in tumour tissue. Cancer cells lack the catalase enzyme to neutralise H₂O₂, while normal cells have adequate catalase. This selective toxicity induces cancer cell death without harming normal tissue. Additionally, Vitamin C supports collagen synthesis (limiting tumour invasion), inhibits HIF-1α (tumour hypoxia signalling), and potentiates chemotherapy.
Cancer Types Studied
Protocols & Dosing
Riordan IVC Protocol
Start with 15 g IV, increase to 25–75 g over 2–4 weeks based on G6PD-adjusted tolerance. Twice weekly alongside oncology treatment. Pre-check G6PD status — deficiency contraindicates high-dose IV-C.
Liposomal Oral Protocol
5–10 g liposomal Vitamin C daily in divided doses. Achieves 3–4x higher plasma levels than standard oral. Use as maintenance between IV sessions.
Bowel Tolerance Oral
Titrate Sodium Ascorbate to just below bowel tolerance (loose stools). Typically 10–25 g daily in divided doses. Use buffered/sodium ascorbate form.
NIH / PubMed Research
Links open on PubMed (National Library of Medicine). Research is ongoing — results may not reflect clinical use.
Cautions & Contraindications
- MUST test for G6PD (glucose-6-phosphate dehydrogenase) deficiency before IV use — can cause haemolytic anaemia
- May cause kidney stones at high doses — maintain high fluid intake
- May interfere with accuracy of glucose monitors (use fingerstick blood glucose, not urine strips)
- Discuss with oncologist — may affect certain chemotherapy drug monitoring
- High-dose oral Vitamin C may cause diarrhoea — titrate to tolerance
Informational only. Not medical advice. Consult your oncologist before starting any alternative or integrative therapy.