Synopsis

Source of validity: Scientific
Rating (out of 5): 2

Vitamin C (ascorbic acid) has a long and complex history regarding its use in cancer prevention and treatment. Scientific interest was sparked in the 1970s when Nobel laureate Linus Pauling and colleagues suggested high-dose vitamin C could help cancer patients, based on early clinical observations and theoretical antioxidant properties. These early studies were not randomized and later randomized controlled trials failed to show a survival benefit for oral vitamin C in cancer patients. More recently, attention has shifted to intravenous (IV) vitamin C, which can achieve much higher plasma concentrations than oral dosing. Preclinical studies suggest that high-dose IV vitamin C may exert pro-oxidant effects selectively toxic to cancer cells and may enhance the efficacy of some chemotherapies. However, large-scale, high-quality clinical trials in humans are still lacking, and the current evidence for vitamin C as a cancer preventive agent remains limited and inconclusive. While some epidemiological studies associate higher vitamin C intake from fruits and vegetables with lower cancer risk, these findings do not establish causality and may reflect overall healthier lifestyles. Major cancer organizations do not currently recommend vitamin C supplements specifically for cancer prevention or treatment outside of clinical trials. In summary, scientific interest exists, and some early-phase research is promising, but the overall evidence supporting vitamin C for cancer prevention is weak at present.

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Other ingredients used for Cancer (prevention)

Other health conditions supported by vitamin C

Products containing vitamin C

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Nature's Sunshine Nutri-Calm
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