Vitamin C megadosage

Chemical structure of vitamin C
3D molecular model of vitamin C

Vitamin C megadosage is a term describing the consumption or injection of vitamin C (ascorbic acid) in doses well beyond the current United States Recommended Dietary Allowance of 90 milligrams per day, and often well beyond the tolerable upper intake level of 2,000 milligrams per day.[1] There is no scientific evidence that vitamin C megadosage helps to cure or prevent cancer, the common cold, or some other medical conditions.[2][3]

Historical advocates of vitamin C megadosage include Linus Pauling, who won the Nobel Prize in Chemistry in 1954. Pauling argued that because humans lack a functional form of L-gulonolactone oxidase, an enzyme required to make vitamin C that is functional in most other mammals, plants, insects, and other life forms, humans have developed a number of adaptations to cope with the relative deficiency. These adaptations, he argued, ultimately shortened lifespan but could be reversed or mitigated by supplementing humans with the hypothetical amount of vitamin C that would have been produced in the body if the enzyme were working.

Vitamin C megadoses are claimed by alternative medicine advocates including Matthias Rath and Patrick Holford to have preventive and curative effects on diseases such as cancer and AIDS,[4] but the available scientific evidence does not support these claims.[3] Some trials show some effect in combination with other therapies, but this does not imply vitamin C megadoses in themselves have any therapeutic effect.[5]

  1. ^ Cite error: The named reference DRItext was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference ACS was invoked but never defined (see the help page).
  3. ^ a b Barret Steven, MD (14 September 2014). "The Dark Side of Linus Pauling's Legacy". www.quackwatch.org. Archived from the original on 4 September 2018. Retrieved 18 December 2018.{{cite web}}: CS1 maint: multiple names: authors list (link)
  4. ^ Bad Science, Ben Goldacre
  5. ^ David Gorski Archived 19 August 2012 at the Wayback Machine, Science Based Medicine, 18 August 2008