Vitamin C

Does vitamin C prevent heart disease or cancer?

Updated 3 Nov 2026

Short answer

Large trials found that it does not. In 14,641 male doctors, 500 mg a day for 8 years did not lower heart attacks, strokes or heart deaths.[1] In 8,171 women at high risk, 500 mg a day for 9.4 years did not change heart events, cancer or cancer deaths.[2][3] A 2022 review for the US Preventive Services Task Force found little or no benefit of vitamin and mineral supplements against heart disease and cancer in healthy adults.[4] For vitamin C, the evidence of benefit was unclear, small or absent.[4]

Sources (4)

  1. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. Sesso HD, Buring JE, Christen WG, Kurth T, Belanger C, MacFadyen J, et al. JAMA, 2008. PMID 18997197
  2. A randomized factorial trial of vitamins C and E and beta carotene in the secondary prevention of cardiovascular events in women: results from the Women's Antioxidant Cardiovascular Study. Cook NR, Albert CM, Gaziano JM, Zaharris E, MacFadyen J, Danielson E, et al. Arch Intern Med, 2007. PMID 17698683
  3. Vitamin C: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  4. Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. O'Connor EA, Evans CV, Ivlev I, Rushkin MC, Thomas RG, Martin A, et al. JAMA, 2022. PMID 35727272

More about vitamin c

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For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.