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Vitamin C megadosage is a term describing the consumption or injection of vitamin C (ascorbate) in doses comparable to the amounts produced by the livers of most other mammals. Such dosages correspond to amounts well beyond the current Dietary Reference Intake. Oral dosages are usually divided and consumed in portions over the day. Injections of hundreds of grams per day are advocated by some physicians for the treatment of certain conditions, poisonings, or recovery from trauma. People who practice vitamin C megadosage may consume many vitamin C pills throughout each day or dissolve pure vitamin C crystals in water or juice and drink it throughout the day. Vitamin C megadoses are claimed by alternative medicine advocates including Matthias Rath and Patrick Holford to have preventative and curative effects on diseases such as cancer and AIDS,〔Bad Science, Ben Goldacre〕〔Trick Or Treatment, Simon Singh & Edzard Ernst〕 but the available scientific evidence does not support these claims.〔(The Dark Side Of Linus Pauling's Legacy ), Quackwatch〕 Some trials show some effect in combination with other therapies, but this does not imply vitamin C megadoses in themselves have therapeutic effect.〔(David Gorski ), Science Based Medicine, 18 Aug 2008〕 ==Background== The World Health Organization recommends a daily intake of 45 milligrams (mg)/day of vitamin C for healthy adults, and 25–30 mg/day in infants. Vitamin C is necessary for production of collagen and other biomolecules, and for the prevention of scurvy. Vitamin C is an antioxidant, which has led to its endorsement by some researchers as a complementary therapy for improving quality of life. Since the 1930s, when it first became available in pure form, some physicians have experimented with higher than recommended vitamin C consumption or injection. Primates, including humans, and guinea pigs do not synthesize vitamin C internally. Vitamin C has been promoted in alternative medicine as a treatment for the common cold, cancer, polio and various other illnesses. The evidence for these claims is mixed. Orthomolecular-based megadose recommendations for vitamin C are based mainly on theoretical speculation and observational studies, such as those published by Fred R. Klenner from the 1940s through the 1970s. There is a strong advocacy movement for such doses of vitamin C, and there is an absence of large scale, formal trials in the 10 to 200+ grams per day range. The single repeatable side effect of oral megadose vitamin C is a mild laxative effect if the practitioner attempts to consume too much too quickly. A tolerable upper limit (UL) of vitamin C was set at 2 grams for the first time in the year 2000, referencing this mild laxative effect as the reason for establishing the UL.〔Institute of Medicine. (Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids ). Washington, DC: The National Academies Press, 2000.〕 Adsorption of orally-delivered vitamin-C is limited to 100mg/day. Oral administration, even of mega doses, cannot raise blood concentration above 0.1mM. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Vitamin C megadosage」の詳細全文を読む スポンサード リンク
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