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

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.

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Dec. 15, 2023 See more Expert Answers

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  25. CAR-T cell therapy
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  29. Chemotherapy and sex: Is sexual activity OK during treatment?
  30. Chemotherapy nausea and vomiting: Prevention is best defense
  31. Chemotherapy side effects: A cause of heart disease?
  32. Complete blood count (CBC)
  33. CT scan
  34. Curcumin: Can it slow cancer growth?
  35. Doppler ultrasound: What is it used for?
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  37. Eating during cancer treatment: Tips to make food tastier
  38. Fertility preservation
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  42. How cancer spreads
  43. Infographic: Cancer Clinical Trials Offer Many Benefits
  44. Infographic: CAR-T Cell Therapy
  45. Infographic: Mayo Clinic CAR-T Cell Therapy Program
  46. Intensity-modulated radiation therapy (IMRT)
  47. Laryngitis
  48. Low blood counts
  49. Magic mouthwash
  50. Medical marijuana
  51. Mindfulness exercises
  52. Monoclonal antibody drugs
  53. Mort Crim and Cancer
  54. Mouth sores caused by cancer treatment: How to cope
  55. MRI
  56. MRI
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  58. Needle biopsy
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  60. Palliative care
  61. PALS (Pets Are Loving Support)
  62. PICC line placement
  63. Pressurized intraperitoneal aerosol chemotherapy (PIPAC)
  64. Proton beam therapy
  65. Proton therapy
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  68. Self-Image During Cancer
  69. Sisters' Bone Marrow Transplant
  70. Sleep tips
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  72. Stem cell transplant
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  76. Ultrasound
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  78. X-ray