Cervical Cancer and Vitamin C

Vitamin C is a powerful antioxidant that neutralizes damaging natural substances called free radicals. It works in water, both inside and outside of cells. Vitamin C complements another antioxidant vitamin, vitamin E, which works in lipid (fatty) parts of the body.

For the treatment of cervical or any other form of cancer, it is important to keep a well-rounded diet, perhaps take herbal supplements, and certainly determine if any of the medications you are taking are creating deficiencies of key nutrients in your body.

Vitamin C is the single most popular vitamin supplement in the United States and perhaps the most controversial, as well. In the 1960s, two-time Nobel Prize winner Dr. Linus Pauling claimed that vitamin C could effectively treat both cancer and the common cold; it is for this reason that it is listed as a possible dietary treatment for cervical cancer. Subsequent research has mostly discounted these claims, but hasn't dampened enthusiasm for this essential nutrient. The vitamin C movement has led to hundreds of clinical studies testing the vitamin on dozens of illnesses; at present, however, no dramatic benefits have been discerned.

Read more details about Vitamin C.

According to a double-blind, placebo-controlled study of 141 women with cervical dysplasia (early cervical cancer), vitamin C, taken at a dosage of 500 mg daily, does not help to reverse the dysplasia.⁷⁵

Observational studies indicate that people with a higher intake of vitamin C have a lower incidence of cataracts, macular degeneration, heart disease, cancer, and osteoarthritis.^22-27,59-66 However, these findings do not indicate that vitamin C supplements will help prevent or treat these conditions. Observational studies are notoriously unreliable for showing the efficacy of treatments; only double-blind studies can do that, and only one has been performed that directly examined vitamin C’s potential benefits for preventing these conditions.

Cancer treatment is one of the more controversial proposed uses of vitamin C. An early study tested vitamin C in 1,100 terminally ill cancer patients. One hundred patients received 10,000 mg daily of vitamin C, while 1,000 other patients (the control group) received no treatment. Those taking the vitamin survived more than four times longer on average (210 days) than those in the control group (50 days).¹⁰² A large (1,826 subjects) follow-up study by the same researchers found a nearly doubled survival rate (343 days versus 180 days) in vitamin C-treated patients whose cancers were deemed "incurable," as compared to untreated controls.¹⁰³ However, these studies were poorly designed, and other generally better-constructed studies have found no benefit of vitamin C in cancer.^104,105 At the present time, vitamin C cannot be regarded as a proven treatment for cancer.

Heated disagreement exists regarding whether it is safe or appropriate to combine antioxidants such as vitamin C with standard chemotherapy drugs. The reasoning behind the concern is that some chemotherapy drugs may work in part by creating free radicals that destroy cancer cells, and antioxidants might interfere with this beneficial effect.^76,166 However, there is no good evidence that antioxidants actually interfere with chemotherapy drugs, but there is growing evidence that they do not.^77,79,151

Safety Issues

The US government has issued recommendations regarding tolerable upper intake levels (ULs) for vitamin C. The UL can be thought of as the highest daily intake over a prolonged time known to pose no risks to most members of a healthy population. The ULs for vitamin C are as follows:

• Children
  • 1-3 years: 400 mg
  • 4-8 years: 650 mg
  • 9-13 years: 1,200 mg

• Males and Females
  • 14-18 years: 1,800 mg
  • 19 years and older: 2,000 mg

• Pregnant Women
  • 18 years old or younger: 1,800 mg
  • 19 years and older: 2,000 mg

• Nursing Women
  • 18 years old or younger: 1,800 mg
  • 19 years and older: 2,000 mg

However, even within the safe intake range for vitamin C, some individuals may develop diarrhea. This side effect will likely go away with continued use of vitamin C, but you might have to cut down your dosage for a while and then gradually build up again.

Concerns have been raised that long-term vitamin C treatment can cause kidney stones . ¹ However, in large-scale observational studies, individuals who consume large amounts of vitamin C have shown either no change or a decreased risk of kidney stone formation. ^{2 3} Still, there may be certain individuals who are particularly at risk for vitamin C-induced kidney stones. ⁴ People with a history of kidney stones and those with kidney failure who have a defect in vitamin C or oxalate metabolism should probably restrict vitamin C intake to approximately 100 mg daily. You should also avoid high-dose vitamin C if you have glucose-6-phosphate dehydrogenase deficiency, iron overload, or a history of intestinal surgery.

Vitamin C supplements increase absorption of iron . ⁵ Since it isn’t good to get more iron than you need, individuals using iron supplements shouldn’t take vitamin C at the same time except under a physician’s supervision.

One study from the 1970s suggests that very high doses of vitamin C (3 g daily) might increase the levels of acetaminophen (such as Tylenol) in the body. ⁶ This could potentially put you at higher risk for acetaminophen toxicity. This interaction is probably relatively unimportant when acetaminophen is taken in single doses for pain and fever, or for a few days during a cold. However, if you use acetaminophen daily or have kidney or liver problems, simultaneous use of high-dose vitamin C is probably not advisable.

Weak evidence suggests that vitamin C, when taken in high doses, might reduce the blood-thinning effects of warfarin (Coumadin) and heparin . ^{7 8 9} As noted above, one study found that vitamin C at a dose of 1 g daily substantially reduced blood levels of the drug indinavir, a protease inhibitor used for the treatment of HIV infection. ¹⁰ Heated disagreement exists regarding whether it is safe or appropriate to combine antioxidants such as vitamin C with standard chemotherapy drugs. The reasoning behind the concern is that some chemotherapy drugs may work in part by creating free radicals that destroy cancer cells, and antioxidants might interfere with this beneficial effect. ¹¹ However, there is no good evidence that antioxidants actually interfere with chemotherapy drugs, but there is growing evidence that they do not. ¹² The maximum safe dosages of vitamin C for people with severe liver or kidney disease have not been determined.

Interactions You Should Know About

If you are taking:

• Aspirin , other anti-inflammatory drugs, or oral contraceptives : You may need more vitamin C.

• Acetaminophen (eg, Tylenol) : The risk of liver damage from high doses of acetaminophen may be increased if you also take large doses of vitamin C.

• Warfarin (Coumadin) or heparin : High-dose vitamin C might reduce their effectiveness.

• Iron supplements: High-dose vitamin C can cause you to absorb too much iron. This is especially a problem for people with diseases that cause them to store too much iron.

• Medications in the nitrate family: Vitamin C may help maintain their effectiveness. Note: Angina is too serious a disease for self-treatment. If you have angina, do not take vitamin C (or any other supplement) except on a physician’s advice.

• Protease inhibitors for HIV: High-dose vitamin C may reduce their effectiveness.

• Cancer chemotherapy : Do not use vitamin C except on physician’s advice.

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2. Curhan GC, Willett WC, Speizer FE, et al. Intake of vitamins B 6 and C and the risk of kidney stones in women. Am Soc Nephrol. 1999;10:840-845.
3. Curhan GC. A prospective study of the intake of vitamin C and vitamin B 6 and the risk of kidney stones in men. J Urol. 1996;155:1847-1851.
4. Auer BL, Auer D, Rodgers AL. Relative hyperoxaluria, crystalluria, and hematuria after mega-dose ingestion of vitamin C. Eur J Clin Invest. 1998;28:695-700.
5. Maskos Z, Koppenol WH. Oxyradicals and multivitamin tablets. Free Radic Biol Med. 11(6):609-10.
6. Houston JB, Levy G. Drug biotransformation interactions in man VI: acetaminophen and ascorbic acid. J Pharm Sci. 65(8):1218-21.
7. Owen CA Jr, Tyce GM, Flock EV, McCall JT. Heparin-ascorbic acid antagonism. Mayo Clin Proc. 45(2):140-5.
8. Rosenthal G. Interaction of ascorbic acid and warfarin [letter]. JAMA. 1971;215:1671.
9. Harris JE. Interaction of dietary factors with oral anticoagulants: review and applications. J Am Diet Assoc. 95(5):580-4.
10. Slain D, Ansden J, Khakoo R, et al. Effects of high-dose vitamin C on the steady state pharmacokinetics of the protease inhibitor Indinavir in healthy volunteers. Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) Meeting; Sept 13-17, 2003; Chicago, IL. Poster A-1610.
11. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology. 1999;13:1003-1012.
12. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treat Rev. 23(4):209-40.

Research Evidence References

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2. Hercberg S, Preziosi P, Galan P, et al. Vitamin status of a healthy French population: Dietary intakes and biochemical markers. Int J Vitam Nutr Res. 1994;64:220-232.

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4. US Department of Agriculture. National Food Consumption Survey. 1985.

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18. Hemila H. Vitamin C intake and susceptibility to the common cold. Br J Nutr. 1997;77:59-72.

19. Peters EM, Goetzsche JM, Grobbelaar B, et al. Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runners. Am J Clin Nutr. 1993;57:170-174.

20. Hemila H. Vitamin C and common cold incidence: a review of studies with subjects under heavy physical stress. Int J Sports Med. 1996;17:379-383.

21. Chappell LC, Seed PT, Briley AL, et al. Effect of antioxidants on the occurrence of pre-eclampsia in women at increased risk: a randomised trial. Lancet. 1999;354:810-816.

22. Hankinson SE, Stampfer MJ, Seddon JM, et al. Nutrient intake and cataract extraction in women: a prospective study. BMJ. 1992;305:335-339.

23. Jacques PF, Taylor A, Hankinson SE, et al. Long-term vitamin C supplement use and prevalence of early age-related lens opacities. Am J Clin Nutr. 1997;66:911-916.

24. Will JC, Byers T. Does diabetes mellitus increase the requirement for vitamin C? Nutr Rev. 1996;54:193-202.

25. Mares-Perlman JA, Klein R, Klein BE, et al. Relationship between age-related maculopathy and intake of vitamin and mineral supplements [abstract]. Invest Ophthalmol Vis Sci. 1993;34:1133.

26. Mares-Perlman JA, Klein R, Klein BE, et al. Association of zinc and antioxidant nutrients with age-related maculopathy. Arch Ophthalmol. 1996;114:991-997.

27. Richter S. Multicenter ophthalmic and nutritional age-related macular degeneration study—Part 2: antioxidant intervention and conclusions. J Am Optom Assoc. 1996;67:30-49.

28. Zollinger PE, Tuinebreijer WE, Kreis RW, et al. Effect of vitamin C on frequency of reflex sympathetic dystrophy in wrist fractures: a randomised trial. Lancet. 1999;354:2025-2028.

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31. Duffy SJ, Gokce N, Holbrook M, et al. Treatment of hypertension with ascorbic acid. Lancet. 1999;354:2048.

32. Osilesi O, Trout DL, Ogunwole JO, et al. Blood pressure and plasma lipids during ascorbic acid supplementation in borderline hypertensive and normotensive adults. Nutr Res. 1991;11:405-412.

33. Fotherby MD, Williams JC, Forster LA, et al. Effect of vitamin C on ambulatory blood pressure and plasma lipids in older persons. J Hypertens. 2000;18:411-415.

34. Ghosh SK, Ekpo EB, Shah IU. A double-blind, placebo-controlled parallel trial of vitamin C treatment in elderly patients with hypertension. Gerontology. 1994;40:268-272.

35. Lovat LB, Lu Y, Palmer AJ, et al. Double-blind trial of vitamin C in elderly hypertensives. J Hum Hypertens. 1993;7:403-405.

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58. Fortner BR Jr, Danziger RE, Rabinowitz PS, et al. The effect of ascorbic acid on cutaneous and nasal response to histamine and allergen. J Allergy Clin Immunol. 1982;69:484-488.

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68. Cameron E, Campbell A. Innovation vs. quality control: an "unpublishable" clinical trial of supplemental ascorbate in incurable cancer. Med Hypotheses. 1991;36:185-189.

69. Creagan ET, Moertel CG, O'Fallon JR, et al. Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial. N Engl J Med. 1979;301:687-690.

70. Moertel CG, Fleming TR, Creagan ET, et al. High-dose vitamin C versus placebo in the treatment of patients with advanced cancer who have had no prior chemotherapy. A randomized double-blind comparison. N Engl J Med. 1985;312:137-141.

71. Harakeh S, Jariwalla RJ, Pauling L. Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells. Proc Natl Acad Sci USA. 1990;87:7245-7249.

72. Cathcart RF III. Vitamin C in the treatment of acquired immune deficiency syndrome (AIDS). Med Hypotheses. 1984;14:423-433.

73. Tang AM, Graham NHM, Kirby AJ, et al. Dietary micronutrient intake and risk of progression to acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus type 1 (HIV-1)-infected homosexual men. Am J Epidemiol. 1993;138:937-951.

74. Allard JP, Aghdassi E, Chau J, et al. Effects of vitamin E and C supplementation on oxidative stress and viral load in HIV-infected subjects. AIDS. 1998;12:1653-1659.

75. Mackerras D, Irwig L, Simpson JM, et al. Randomized double-blind trial of beta-carotene and vitamin C in women with minor cervical abnormalities. Br J Cancer. 1999;79:1448-1453.

76. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology. 1999;13:1003-1012.

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79. Kurbacher CM, Wagner U, Kolster B, et al. Ascorbic acid (vitamin C) improves the antineoplastic activity of doxorubicin, cisplatin, and paclitaxel in human breast carcinoma cells in vitro. Cancer Lett. 1996;103:183-189.

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82. Hemila H. Vitamin C supplementation and common cold symptoms: factors affecting the magnitude of the benefit. Med Hypotheses. 1999;52:171-178.

83. Hemila H. Vitamin C supplementation and common cold symptoms: factors affecting the magnitude of the benefit. Med Hypotheses. 1999;52:171-178.

84. Peters EM, Goetzsche JM, Grobbelaar B, et al. Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runners. Am J Clin Nutr. 1993;57:170-174.

85. Hemila H. Vitamin C and common cold incidence: a review of studies with subjects under heavy physical stress. Int J Sports Med. 1996;17:379-383.

86. Hemila H. Vitamin C intake and susceptibility to the common cold. Br J Nutr. 1997;77:59-72.

87. Peters EM, Goetzsche JM, Grobbelaar B, et al. Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runners. Am J Clin Nutr. 1993;57:170-174.

88. Hemila H. Vitamin C and common cold incidence: a review of studies with subjects under heavy physical stress. Int J Sports Med. 1996;17:379-383.

89. Hemila H. Vitamin C and common cold incidence: a review of studies with subjects under heavy physical stress. Int J Sports Med. 1996;17:379-383.

90. Hankinson SE, Stampfer MJ, Seddon JM, et al. Nutrient intake and cataract extraction in women: a prospective study. BMJ. 1992;305:335-339.

91. Jacques PF, Taylor A, Hankinson SE, et al. Long-term vitamin C supplement use and prevalence of early age-related lens opacities. Am J Clin Nutr. 1997;66:911-916.

92. Will JC, Byers T. Does diabetes mellitus increase the requirement for vitamin C? Nutr Rev. 1996;54:193-202.

93. Mares-Perlman JA, Klein R, Klein BE, et al. Relationship between age-related maculopathy and intake of vitamin and mineral supplements [abstract]. Invest Ophthalmol Vis Sci. 1993;34:1133.

94. Mares-Perlman JA, Klein R, Klein BE, et al. Association of zinc and antioxidant nutrients with age-related maculopathy. Arch Ophthalmol. 1996;114:991-997.

95. Richter S. Multicenter ophthalmic and nutritional age-related macular degeneration study—Part 2: antioxidant intervention and conclusions. J Am Optom Assoc. 1996;67:30-49.

96. Chappell LC, Seed PT, Briley AL, et al. Effect of antioxidants on the occurrence of pre-eclampsia in women at increased risk: a randomised trial. Lancet. 1999;354:810-816.

97. Bruemmer B, White E, Vaughan TL, et al. Nutrient intake in relation to bladder cancer among middle-aged men and women. Am J Epidemiol. 1996;144:485-495.

98. O'Toole P, Lombard M. Vitamin C and gastric cancer: Supplements for some or fruit for all. Gut. 1996;39:345-347.

99. Greenberg ER, Baron JA, Tosteson TD, et al. A clinical trial of antioxidant vitamins to prevent colorectal adenoma. Polyp Prevention Study Group. N Engl J Med. 1994;331:141-147.

100. Kushi L, Fee R, Sellers T, et al. Intake of vitamins A, C, and E and postmenopausal breast cancer. The Iowa Women's Health Study. Am J Epidemiol. 1996;144:165-174.

101. Hunter DJ, Manson JE, Colditz GA, et al. A prospective study of the intake of vitamins C, E, and A and the risk of breast cancer. N Engl J Med. 1993;329:234-240.

102. Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: Prolongation of survival times in terminal human cancer. Proc Natl Acad Sci USA. 1976;73:3685-3689.

103. Cameron E, Campbell A. Innovation vs. quality control: an "unpublishable" clinical trial of supplemental ascorbate in incurable cancer. Med Hypotheses. 1991;36:185-189.

104. Creagan ET, Moertel CG, O'Fallon JR, et al. Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial. N Engl J Med. 1979;301:687-690.

105. Moertel CG, Fleming TR, Creagan ET, et al. High-dose vitamin C versus placebo in the treatment of patients with advanced cancer who have had no prior chemotherapy. A randomized double-blind comparison. N Engl J Med. 1985;312:137-141.

106. Ness AR, Powles JW, Khaw KT. Vitamin C and cardiovascular disease: a systematic review. J Cardiovasc Risk. 1996;3:513-521.

107. Simon JA. Vitamin C and cardiovascular disease: a review. J Am Coll Nutr. 1992;11:107-125.

108. Trout DL. Vitamin C and cardiovascular risk factors. Am J Clin Nutr. 1991;53(suppl 1):322S-325S.

109. Losonczy KG, Harris TB, Havlik RJ. Vitamin E and vitamin C supplement use and risk of all-cause and coronary heart disease mortality in older persons: the Established Populations for Epidemiologic Studies of the Elderly. Am J Clin Nutr. 1996;64:190-196.

110. Zollinger PE, Tuinebreijer WE, Kreis RW, et al. Effect of vitamin C on frequency of reflex sympathetic dystrophy in wrist fractures: a randomised trial. Lancet. 1999;354:2025-2028.

111. Schorah CJ, Tormey WP, Brooks GH, et al. The effect of vitamin C supplements on body weight, serum proteins, and general health of an elderly population. Am J Clin Nutr. 1981;34:871-876.

112. Duffy SJ, Gokce N, Holbrook M, et al. Treatment of hypertension with ascorbic acid. Lancet. 1999;354:2048.

113. Osilesi O, Trout DL, Ogunwole JO, et al. Blood pressure and plasma lipids during ascorbic acid supplementation in borderline hypertensive and normotensive adults. Nutr Res. 1991;11:405-412.

114. Fotherby MD, Williams JC, Forster LA, et al. Effect of vitamin C on ambulatory blood pressure and plasma lipids in older persons. J Hypertens. 2000;18:411-415.

115. Ghosh SK, Ekpo EB, Shah IU. A double-blind, placebo-controlled parallel trial of vitamin C treatment in elderly patients with hypertension. Gerontology. 1994;40:268-272.

116. Lovat LB, Lu Y, Palmer AJ, et al. Double-blind trial of vitamin C in elderly hypertensives. J Hum Hypertens. 1993;7:403-405.

117. Milne DB, Klevay LM, Hunt JR. Effects of ascorbic acid supplements and a diet marginal in copper on indices of copper nutriture in women. Nutr Res. 1988;8:865-873.

118. Finley EB, Cerklewski FL. Influence of ascorbic acid supplementation on copper status in young adult men. Am J Clin Nutr. 1983;37:553-556.

119. Jacob RA, Skala JH, Omaye ST, et al. Effect of varying ascorbic acid intakes on copper absorption and ceruloplasmin levels of young men. J Nutr. 1987;117:2109-2115.

120. Harris ED, Percival SS. A role for ascorbic acid in copper transport. Am J Clin Nutr. 1991;54(suppl 6):1193S-1197S.

121. Maskos Z, Koppenol WH. Oxyradicals and multivitamin tablets. Free Radic Biol Med. 1991;11:609-610.

122. Conrad ME, Schade SG. Ascorbic acid chelates in iron absorption: a role for hydrochloric acid and bile. Gastroenterology. 1968;55:35-45.

123. Brise H, Hallberg L. Effect of ascorbic acid on iron absorption. Acta Med Scand. 1962;171(suppl 376):51.

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