Megavitamin therapy
ClaimsHealth effects from very high doses of vitamins.
Related scientific disciplinesvitamins, dietary supplements
Year proposed1930s
Notable proponentsFrederick Klenner, Linus Pauling
(Overview of pseudoscientific concepts)

Megavitamin therapy is the use of large doses of vitamins, often many times greater than the recommended dietary allowance (RDA) in the attempt to prevent or treat diseases. Megavitamin therapy is typically used in alternative medicine by practitioners who call their approach orthomolecular medicine.[1] Vitamins are useful in preventing and treating illnesses specifically associated with dietary vitamin shortfalls, but the conclusions of medical research are that the broad claims of disease treatment by advocates of megavitamin therapy are unsubstantiated by the available evidence.[2][3] It is generally accepted that doses of any vitamin greatly in excess of nutritional requirements will result either in toxicity (vitamins A and D) or in the excess simply being metabolised; thus evidence in favour of vitamin supplementation supports only doses in the normal range.[4][5][6] Critics have described some aspects of orthomolecular medicine as food faddism or even quackery.[7][8][9] Research on nutrient supplementation in general suggests that some nutritional supplements might be beneficial, and that others might be harmful;[10][11][12] several specific nutritional therapies are associated with an increased likelihood of the condition they are meant to prevent.[13]

Multivitamin vs megavitamin

Megavitamin therapy must be distinguished from the usual "vitamin supplementation" approach of traditional multivitamin pills. Megavitamin doses are far higher than the levels of vitamins ordinarily available through western diets. A study of 161,000 individuals (post-menopausal women) provided, in the words of the authors, "convincing evidence that multivitamin use has little or no influence on the risk of common cancers, cardiovascular disease, or total mortality in postmenopausal women".[14]


In the 1930s and 1940s, some scientific and clinical evidence suggested that there might be beneficial uses of vitamins C, E, and niacin in large doses. Beginning in the 1930s in Canada, a megadose vitamin E therapy for cardiovascular and circulatory complaints was developed by Evan Shute and colleagues, named the "Shute protocol".[15] Tentative experiments in the 1930s by Claus W. Jungeblut[16] with larger doses of vitamin C led to Frederick Klenner's development of megadose intravenous vitamin C treatments for polio and other viruses in the 1940s.[17] William Kaufman published articles in the 1940s that detailed his treatment of arthritis with frequent, high doses of niacinamide.[18] Rudolf Altschul and Abram Hoffer applied large doses of the immediate release form of niacin (Vitamin B3) to treat hypercholesterolemia.[19][20] In a 1956 publication entitled Biochemical Individuality, Roger J. Williams introduced concepts for individualized megavitamins and nutrients.[21] Megavitamin therapies were also publicly advocated by Linus Pauling in the late 1960s.[22]

Usage as therapy

Although megavitamin therapies still largely remain outside of the structure of evidence-based medicine, they are increasingly used by patients, with or without the approval of their treating physicians, often after recommendations by practitioners of orthomolecular and naturopathic medicine.[23] The proposed efficacy of various megavitamin therapies to reduce cancer risk has been contradicted by results of one clinical trial.[24]

Vitamin C

Main article: Vitamin C megadosage

The US Recommended Dietary Allowance for vitamin C for adult women is 76 mg/day and for adult men 90 mg/day. Although Linus Pauling was known for highly respectable research in chemistry and biochemistry, he was also known for promoting the consumption of vitamin C in large doses.[25] Although he claimed and stood firm in his claim that consuming over 1,000 mg is helpful for one’s immune system when fighting a head cold, the results of empirical research do not align with this view. A meta-analysis concluded that supplementary vitamin C significantly lowered serum uric acid, considered a risk factor for gout.[26] One population study reported an inverse correlation between dietary vitamin C and risk of gout.[27] A review of clinical trials in the treatment of colds with small and large doses of Vitamin C has established that there is no evidence that it decreases the incidence of common colds.[28] After 33 years of research, it is still not established whether vitamin C can be used as a treatment for cancer.[29]

Vitamin E

The US Recommended Dietary Allowance for vitamin E for adult women and men is 15 mg/day. The US Food and Nutrition Board set a tolerable upper intake level (UL) at 1,000 mg (1,500 IU) per day derived from animal models that demonstrated bleeding at high doses.[30] In the US, the popularity for vitamin E as a dietary supplement peaked around 2000, with popular doses of 400, 800 and 1000 IU/day. Declines in usage were attributed to publications of studies that showed either no benefits or negative consequences from vitamin E supplements.[31] One meta-analysis showed no association between vitamin E supplementation and cardiovascular events (nonfatal stroke or myocardial infarction) or cardiovascular mortality.[32] Another meta-analysis concluded that high-dosage vitamin E increased all-cause mortality.[33]


The US Recommended Dietary Allowance for niacin for adult women is 14 mg/day and for adult men 16 mg/day. Niacin is available as a prescription product, either immediate release (500 mg tablets; prescribed up to 3,000 mg/day) or extended release (500 and 1,000 mg tablets; prescribed up to 2,000 mg/day). In the US, niacin is also available as a dietary supplement at 500 to 1,000 mg/tablet. Niacin has sometimes been used in combination with other lipid-lowering medications.[34] Systematic reviews found no effect of niacin on cardiovascular disease or death, in spite of raising high-density lipoprotein (HDL) cholesterol. Reported side effects include an increased risk of diabetes.[35][36][37]

See also

Related topics

Vitamin topics


  1. ^ Zell M, Grundmann O (2012). "An orthomolecular approach to the prevention and treatment of psychiatric disorders". Adv Mind Body Med. 26 (2): 14–28. PMID 23341413.
  2. ^ Aaronson S, et al. (2003). "Cancer medicine". Cancer medicine 6 (Frei, Emil; Kufe, Donald W.; Holland, James F., eds). Hamilton, Ont: BC Decker. pp. 76. ISBN 978-1-55009-213-4.
  3. ^ Nutrition Committee, Canadian Paediatric Society (1990). "Megavitamin and megamineral therapy in childhood. Nutrition Committee, Canadian Paediatric Society". CMAJ. 143 (10): 1009–1013. PMC 1452516. PMID 1699646.
  4. ^ "What Does Your Body do to Excess Vitamin B or C That You Might Consume?". 16 June 2012.
  5. ^ "Vitamins & Supplements Center – Nutritional, Herbal, Dietary, and More - WebMD".
  6. ^ Novella, S: Medical Myths, Lies, and Half-Truths: What We Think We Know May Be Hurting Us, The Great Courses
  7. ^ Jarvis WT (1983). "Food faddism, cultism, and quackery". Annu. Rev. Nutr. 3: 35–52. doi:10.1146/ PMID 6315036.
  8. ^ Jukes TH (1990). "Nutrition Science from Vitamins to Molecular Biology". Annual Review of Nutrition. 10 (1): 1–20. doi:10.1146/ PMID 2200458. A short summary is in the journal's preface.
  9. ^ Braganza, S.F., Ozuah, P.O. (2005). "Fad Therapies". Pediatrics in Review. 26 (10): 371–376. doi:10.1542/pir.26-10-371. PMID 16199591.
  10. ^ "NIH State-of-the-Science Conference Statement on Multivitamin/Mineral Supplements and Chronic Disease Prevention". NIH Consens State Sci Statements. 23 (2): 1–30. 2006. PMID 17332802. Archived from the original on 2009-02-21. Retrieved 2009-02-18.
  11. ^ Huang HY, Caballero B, Chang S, et al. (2006). "The efficacy and safety of multivitamin and mineral supplement use to prevent cancer and chronic disease in adults: a systematic review for a National Institutes of Health state-of-the-science conference". Ann. Intern. Med. 145 (5): 372–385. doi:10.1001/archinte.145.2.372. PMID 16880453.
  12. ^ Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C (2012). "Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases". Cochrane Database Syst Rev. 2012 (3): CD007176. doi:10.1002/14651858.CD007176.pub2. hdl:10138/136201. PMC 8407395. PMID 22419320.
  13. ^ Satia JA, Littman A, Slatore CG, Galanko JA, White E (2009). "Long-term Use of {beta}-Carotene, Retinol, Lycopene, and Lutein Supplements and Lung Cancer Risk: Results From the VITamins And Lifestyle (VITAL) Study". American Journal of Epidemiology. 169 (7): 815–828. doi:10.1093/aje/kwn409. PMC 2842198. PMID 19208726.
  14. ^ Neuhouser ML, Wassertheil-Smoller S, Thomson C, et al. (2009). "Multivitamin use and risk of cancer and cardiovascular disease in the Women's Health Initiative cohorts". Arch. Intern. Med. 169 (3): 294–304. doi:10.1001/archinternmed.2008.540. PMC 3868488. PMID 19204221.
  15. ^ Vogelsang A, Shute E, Shute W (1948). "Some medical uses of vitamin E". Med World (New York). 161 (2): 83–89. PMID 18911314.
  16. ^ Jungeblut CW (1937). "Vitamin C Therapy and Prophylaxis in Experimental Poliomyelitis". The Journal of Experimental Medicine. 65 (1): 127–146. doi:10.1084/jem.65.1.127. PMC 2133474. PMID 19870585.
  17. ^ Klenner, Fred R. (1949). "The treatment of poliomyelitis and other virus diseases with vitamin C". Southern Medicine & Surgery. 111 (7): 209–214. PMID 18147027.
  18. ^ KAUFMAN W (July 1953). "Niacinamide therapy for joint mobility; therapeutic reversal of a common clinical manifestation of the normal aging process". Conn State Med J. 17 (7): 584–9. PMID 13060032.
  19. ^ Altschul R, Hoffer A, Stephen JD (1955). "Influence of nicotinic acid on serum cholesterol in man". Arch. Biochem. Biophys. 54 (2): 558–559. doi:10.1016/0003-9861(55)90070-9. PMID 14350806.
  20. ^ Altschul R, Hoffer A (1960). "The Effect of Nicotinic Acid on Hypercholesterolæmia". Can Med Assoc J. 82 (15): 783–785. PMC 1938010. PMID 13792994.
  21. ^ Williams, Roger Lawrence (1998). Biochemical Individuality. New York: McGraw-Hill. ISBN 978-0-87983-893-5.
  22. ^ Stone, Irwin (1982). The healing factor: "vitamin C" against disease. New York: Perigee Books. ISBN 978-0-399-50764-9.
  23. ^ Richardson MA, Sanders T, Palmer JL, Greisinger A, Singletary SE (2000). "Complementary/alternative medicine use in a comprehensive cancer center and the implications for oncology". J. Clin. Oncol. 18 (13): 2505–2514. doi:10.1200/JCO.2000.18.13.2505. PMID 10893280.
  24. ^ Lin J, Cook NR, Albert C, et al. (2009). "Vitamins C and E and Beta Carotene Supplementation and Cancer Risk: A Randomized Controlled Trial". J. Natl. Cancer Inst. 101 (1): 14–23. doi:10.1093/jnci/djn438. PMC 2615459. PMID 19116389.
  25. ^ Cameron E, Pauling L (October 1976). "Supplemental ascorbate in the supportive treatment of cancer: Prolongation of survival times in terminal human cancer". Proceedings of the National Academy of Sciences of the United States of America. 73 (10): 3685–9. Bibcode:1976PNAS...73.3685C. doi:10.1073/pnas.73.10.3685. PMC 431183. PMID 1068480.
  26. ^ Juraschek SP, Miller ER, Gelber AC (September 2011). "Effect of oral vitamin C supplementation on serum uric acid: a meta-analysis of randomized controlled trials". Arthritis Care & Research. 63 (9): 1295–306. doi:10.1002/acr.20519. PMC 3169708. PMID 21671418.
  27. ^ Choi HK, Xiang Gao, Gary Curhan (2009). "Vitamin C Intake and the Risk of Gout in Men – A Prospective Study". Archives of Internal Medicine. 169 (5): 502–507. doi:10.1001/archinternmed.2008.606. PMC 2767211. PMID 19273781.
  28. ^ Hemilä H, Chalker E (2013-01-31). "Vitamin C for preventing and treating the common cold". The Cochrane Database of Systematic Reviews. 2013 (1): CD000980. doi:10.1002/14651858.CD000980.pub4. ISSN 1469-493X. PMC 1160577. PMID 23440782.
  29. ^ Cabanillas F (2010). "Vitamin C and cancer: what can we conclude--1,609 patients and 33 years later?". Puerto Rico Health Sciences Journal. 29 (3): 215–217. PMID 20799507.
  30. ^ Institute of Medicine (2000). "Vitamin E". Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: The National Academies Press. pp. 186–283. doi:10.17226/9810. ISBN 978-0-309-06935-9. PMID 25077263.
  31. ^ Kim HJ, Giovannucci E, Rosner B, Willett WC, Cho E (2014). "Longitudinal and secular trends in dietary supplement use: Nurses' Health Study and Health Professionals Follow-Up Study, 1986-2006". J Acad Nutr Diet. 114 (3): 436–443. doi:10.1016/j.jand.2013.07.039. PMC 3944223. PMID 24119503.
  32. ^ Eidelman RS, Hollar D, Hebert PR, Lamas GA, Hennekens CH (2004). "Randomized trials of vitamin E in the treatment and prevention of cardiovascular disease". Archives of Internal Medicine. 164 (14): 1552–1556. doi:10.1001/archinte.164.14.1552. PMID 15277288.
  33. ^ Miller ER, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E (2005). "Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality". Ann. Intern. Med. 142 (1): 37–46. doi:10.7326/0003-4819-142-1-200501040-00110. PMID 15537682.
  34. ^ Niacin tablet label Updated March 14, 2013. Page accessed Feb 11, 2016
  35. ^ Keene D, Price C, Shun-Shin MJ, Francis DP (July 2014). "Effect on cardiovascular risk of high density lipoprotein targeted drug treatments niacin, fibrates, and CETP inhibitors: meta-analysis of randomised controlled trials including 117,411 patients". BMJ. 349: g4379. doi:10.1136/bmj.g4379. PMC 4103514. PMID 25038074.
  36. ^ Schandelmaier S, Briel M, Saccilotto R, Olu KK, Arpagaus A, Hemkens LG, Nordmann AJ (June 2017). "Niacin for primary and secondary prevention of cardiovascular events". The Cochrane Database of Systematic Reviews. 2017 (6): CD009744. doi:10.1002/14651858.CD009744.pub2. PMC 6481694. PMID 28616955.
  37. ^ Garg A, Sharma A, Krishnamoorthy P, Garg J, Virmani D, Sharma T, Stefanini G, Kostis JB, Mukherjee D, Sikorskaya E (2017). "Role of Niacin in Current Clinical Practice: A Systematic Review". The American Journal of Medicine. 130 (2): 173–187. doi:10.1016/j.amjmed.2016.07.038. PMID 27793642.