I've heard that vitamin C might be an alternative cancer treatment. What can you tell me about it?

Answer From Karthik Giridhar, M.D.

Interest in using very high doses of vitamin C as a cancer treatment began as long ago as the 1970s when it was discovered that some properties of the vitamin may make it toxic to cancer cells. Initial studies in humans had promising results, but these studies were later found to be flawed.

Subsequent well-designed, randomized, controlled trials of vitamin C in pill form found no such benefits for people with cancer. Despite the lack of evidence, some alternative medicine practitioners continue to recommend high doses of vitamin C for cancer treatment.

More recently, vitamin C given through a vein (intravenously) has been found to have different effects than vitamin C taken in pill form. This has prompted renewed interest in the use of vitamin C as a cancer treatment.

There's still no evidence that vitamin C alone can cure cancer, but researchers are studying whether it might boost the effectiveness of other cancer treatments, such as chemotherapy and radiation therapy, or reduce treatment side effects.

There are still no large, controlled clinical trials that have shown a substantial effect of vitamin C on cancer, but some preliminary studies do suggest there may be a benefit to combining standard treatments with high-dose IV vitamin C. Until clinical trials are completed, it's premature to determine what role vitamin C may play in the treatment of cancer.

With

Karthik Giridhar, M.D.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Dec. 15, 2023 See more Expert Answers

See also

  1. Health foods
  2. Adjuvant therapy for cancer
  3. Alternative cancer treatments: 11 options to consider
  4. Atypical cells: Are they cancer?
  5. Biological therapy for cancer
  6. Biopsy procedures
  7. Blood Basics
  8. Bone marrow transplant
  9. Bone scan
  10. Cancer
  11. Cancer
  12. Cancer blood tests
  13. Myths about cancer causes
  14. Infographic: Cancer Clinical Trials Offer Many Benefits
  15. Cancer diagnosis: 11 tips for coping
  16. Cancer-related fatigue
  17. Cancer pain: Relief is possible
  18. Cancer-prevention strategies
  19. Cancer risk: What the numbers mean
  20. Cancer surgery
  21. Cancer survival rate
  22. Cancer survivors: Care for your body after treatment
  23. Cancer survivors: Late effects of cancer treatment
  24. Cancer survivors: Managing your emotions after cancer treatment
  25. Cancer survivorship program
  26. Cancer treatment
  27. Cancer treatment myths
  28. Cancer-related fatigue
  29. Cancer-related pain
  30. Cancer-related weakness
  31. Chemo targets
  32. Chemoembolization
  33. Chemotherapy
  34. Chemotherapy and hair loss: What to expect during treatment
  35. Chemotherapy and sex: Is sexual activity OK during treatment?
  36. Chemotherapy nausea and vomiting: Prevention is best defense
  37. Chemotherapy side effects: A cause of heart disease?
  38. Complete blood count (CBC)
  39. Cough
  40. CT scan
  41. Curcumin: Can it slow cancer growth?
  42. Cancer-related diarrhea
  43. Eating during cancer treatment: Tips to make food tastier
  44. Fatigue
  45. Fertility preservation
  46. Heart cancer: Is there such a thing?
  47. Honey: An effective cough remedy?
  48. Infographic: CAR-T Cell Therapy
  49. Intensity-modulated radiation therapy (IMRT)
  50. Intrathecal chemotherapy
  51. Joint pain
  52. Low blood counts
  53. Magic mouthwash
  54. Medical marijuana
  55. Microwave ablation for cancer
  56. Mindfulness exercises
  57. Minimally invasive cancer surgery
  58. Monoclonal antibody drugs
  59. Mort Crim and Cancer
  60. Mouth sores caused by cancer treatment: How to cope
  61. MRI
  62. Muscle pain
  63. Needle biopsy
  64. Night sweats
  65. No appetite? How to get nutrition during cancer treatment
  66. Palliative care
  67. PALS (Pets Are Loving Support)
  68. Pelvic exenteration
  69. PET/MRI scan
  70. Precision medicine for cancer
  71. Radiation therapy
  72. Seeing inside the heart with MRI
  73. Self-Image During Cancer
  74. Sentinel lymph node mapping
  75. Sisters' Bone Marrow Transplant
  76. Sleep tips
  77. Small cell, large cell cancer: What this means
  78. Stem Cells 101
  79. Stem cells: What they are and what they do
  80. Surgical biopsy
  81. Tumor vs. cyst: What's the difference?
  82. TVEC (Talimogene laherparepvec) injection
  83. Ultrasound
  84. Unexplained weight loss
  85. Stem cell transplant
  86. How cancer spreads
  87. MRI
  88. PICC line placement
  89. When cancer returns: How to cope with cancer recurrence
  90. Wide local skin excision
  91. X-ray