Although most animals can make vitamin C from scratch, humans have lost the ability over the course of evolution. We must get it from food, chiefly fresh fruits and vegetables. One of this vitamin's main functions is helping the body manufacture collagen, a key protein in our connective tissues, cartilage, and tendons.
From ancient times through the early nineteenth century, sailors and others deprived of fresh fruits and vegetables developed a disease called scurvy. Scurvy involves so-called scorbutic symptoms, which include nonhealing wounds, bleeding gums, bruising, and overall weakness. Now we know that scurvy is nothing more than vitamin C deficiency.
Scurvy was successfully treated with citrus fruit during the mid-1700s. In 1928, when Albert Szent-Gyorgyi isolated the active ingredient, he called it the anti-scorbutic principle, or ascorbic acid. This, of course, is 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.
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. 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.
Vitamin C is an essential nutrient that must be obtained from food or supplements; the body cannot manufacture it. The official US and Canadian recommendations for daily intake are as follows:
Vitamin C supplements are available in two forms: ascorbic acid and ascorbate. The latter is less intensely sour.
Most of us think of orange juice as the quintessential source of vitamin C, but many vegetables contain as much or even more. The National Institutes of Health's Office of Dietary Supplements offers this list of foods that are high in vitamin C:188
Vitamin C content
|% Daily Value|
|Sweet red pepper, raw||½ cup||95||158|
|Orange juice||¾ cup||93||155|
|Grapefruit juice||¾ cup||70||117|
|Green pepper, raw||½ cup||60||100|
|Broccoli, cooked||½ cup||51||85|
|Strawberries, fresh||½ cup||49||82|
|Brussels sprouts, cooked||½ cup||48||80|
|Broccoli, raw||½ cup||39||65|
|Tomato juice||¾ cup||33||55|
|Cabbage, cooked||½ cup||28||47|
|Cauliflower, raw||½ cup||26||43|
|Potato, baked||1 medium||17||28|
|Tomato, raw||1 medium||17||28|
|Spinach, cooked||½ cup||9||15|
|Green beans, cooked||½ cup||8||13|
One great advantage of getting vitamin C from foods rather than from supplements is that you will get many other potentially healthful nutrients at the same time, such as bioflavonoids and carotenes. However, vitamin C in food is partially destroyed by cooking and exposure to air, so for maximum nutritional benefit you might want to try freshly made salads rather than dishes that require a lot of cooking.
Scurvy, the classic vitamin C deficiency disease, is now a rarity in the developed world, although a more subtle deficiency of vitamin C is fairly common.2-6 According to one study, 40% of Americans do not get enough vitamin C.7 In fact, vitamin C deficiency sufficient to cause bleeding problems during surgery turns out to be more common than previously thought.141
Ever since Linus Pauling, proponents have recommended taking vitamin C in enormous doses, as high as 20,000 mg to 30,000 mg daily. However, some evidence suggests that there might not be any reason to take more than 200 mg of vitamin C daily (10 to 100 times less than the amount recommended by vitamin C proponents).16 The reason is that if you consume more than 200 mg daily (researchers have tested up to 2,500 mg) your kidneys begin to excrete the excess at a steadily increasing rate, matching the increased dose. Your digestive tract also stops absorbing it well. The net effect is that no matter how much you take, your blood levels of vitamin C don't increase very much.
However, there are some flaws in this research. It is possible that vitamin C levels might rise in other tissues even if they remain constant in the blood. Furthermore, this study did not evaluate the possible effects of taking vitamin C several times daily rather than once daily.
Many nutritional experts recommend a total of 500 mg of vitamin C daily. This dose is almost undoubtedly safe. Others recommend that you take as much vitamin C as you can, up to 30,000 mg daily, cutting back only when you start to develop stomach cramps and diarrhea. This recommendation seems based more on a semi-religious enthusiasm for the vitamin C than on any evidence that such huge doses of the vitamin are good for you.
Intravenous vitamin C can easily raise vitamin C levels to a level 140 times higher than the maximum achievable with oral vitamin C.152 However, there is no meaningful evidence that intravenous vitamin C provides any medical benefits.
According to numerous double-blind, placebo-controlled studies, regular use of vitamin C supplements can slightly reduce symptoms of colds and modestly shorten the length of the illness.17,18,146,185 However, taking vitamin C at the onset of a cold probably does not work.83,140, 185
Regular use of vitamin C does not seem to help prevent colds.86,146,185 One exception is the “post-marathon sniffle”—colds that develop after heavy exercise.19,20 Vitamin C may be helpful for preventing this condition, although not all studies agree.153
A review of 3 randomized studies involving 2,335 people found that vitamin C may reduce the risk of pneumonia in adolescents and adults, .187 The benefits of vitamin C appeared to be largely restricted to people at an increased risk of getting pneumonia and those with low dietary intake of the vitamin. The authors concluded that the widespread use of supplemental vitamin C to prevent pneumonia was not supported by their review.
Two double-blind studies suggest that the use of vitamin C combined with vitamin E might slightly reduce the risk of developing preeclampsia, a complication of pregnancy.21,169 However, a much larger follow-up study failed to find benefits.170
Two studies conducted by a single research group have found that vitamin C at a dose of 500 mg daily might help prevent reflex sympathetic dystrophy, a poorly understood condition that can follow injuries such as fractures.110,180
Over time, the body develops tolerance to drugs in the nitrate family (such as nitroglycerin). Some evidence suggests that use of vitamin C can help maintain the effectiveness of these medications.142-145
Other small double-blind trials suggest that vitamin C might be helpful for anterior uveitis (when taken in combination with vitamin E),52autism,40easy bruising,29minor injuries,41 protecting the liver in nonalcoholic steatohepatitis,154 speeding recovery from bedsores,37 treating female infertility (specifically, a condition called "luteal phase defect"),155 and preventing early rupture of the chorioamniotic membranes ("the water breaking") in pregnancy.156 Vitamin C might also improve the effectiveness of antibiotic treatment for Helicobacter pylori, the cause of most peptic ulcers.179 Given the limited nature of this research, however, further studies are needed to conclude that vitamin C is beneficial for these conditions.
Preliminary evidence suggests that cream containing vitamin C may improve the appearance of aging or sun-damaged skin.50,51,157 Inconsistent evidence suggests that oral or topical vitamin C, taken by itself or in combination with vitamin E, may also help protect the skin against sun damage.42-49
Double-blind studies of vitamin C for the following conditions have yielded mixed results: asthma,30, 178male infertility,38,39 reducing the muscle soreness that typically develops after exercise,36,176,177 and hypertension.31-35,147,148Note: Unexpectedly, one study found that a combination of vitamin C (500 mg daily) and grape seed oligomeric proanthocyanidins (OPCs) (1,000 mg daily) slightly increased blood pressure.158 Whether this was a fluke of statistics or a real combined effect remains unclear.
Limited and in some cases contradictory evidence suggests possible benefit in the prevention or treatment the following conditions:
Intravaginal use of vitamin C tablets might be helpful for non-specific vaginitis.159
Observational studies indicate that people with a higher intake of vitamin C have a lower incidence of 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. (For more information on why double-blind studies are so important, see Why Does This Database Rely on Double-blind Studies? ) Two large double-blind trials exploring the effectiveness of vitamin C for heart disease prevention—one in women at high risk 181 and the other in men at low risk— 183 failed to find any benefit at all.
Vitamin C has been proposed as a treatment for cancer, but this claim is very controversial, and there is as yet no scientifically meaningful evidence that it works.67-70
Massive doses of vitamin C have at times been popular among people with HIV infection based on highly preliminary evidence.71,72 An observational study linked high doses of vitamin C with slower progression to AIDS.73 However, a double-blind study of 49 people with HIV who took combined vitamins C and E or placebo for 3 months did not show any significant effects on the amount of HIV detected or the number of opportunistic infections.74 Furthermore, 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.160 This could potentially cause the drug to fail.
In a study of 80 women with Chlamydia trachomatis infection, adding vitamin C to doxycycline and triple sulfa vaginal cream reduced discharge and pain associated with intercourse.184
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
As the most famous of all natural treatments for the common cold, vitamin C has been subjected to irresponsible hype from both proponents and opponents. Enthusiasts claim that if you take vitamin C daily, you will never get sick, while critics of the treatment insist that vitamin C has no benefit at all.
However, a cool-headed evaluation of the research indicates something in between. Numerous studies have found that vitamin C supplements taken at a dose of 1,000 mg daily or more throughout the cold season can modestly reduce symptoms of colds and help you get over a cold faster, but they do not generally help prevent colds.81,83,146,162,185
Most studies on vitamin C have evaluated the potential benefits to be gained by taking vitamin C throughout the cold season. A review of 29 placebo-controlled trials involving over 11,000 people found that the use of vitamin C in this way can reduce symptoms and decrease the duration of colds.185 Other studies have found similar results.81,83
Many people use vitamin C for colds in a different way: they only begin taking it when cold symptoms start. Vitamin C is probably not effective when used in this way.83,140,185 One double-blind trial enrolled 400 individuals with new-onset cold symptoms, and divided them into four different daily vitamin C dosage groups: 30 mg daily (a dose lower than the minimum daily requirement, and used by the researchers as a placebo), 1,000 mg, 3,000 mg, or 3,000 mg with bioflavonoids.140 Participants were instructed to take the vitamin at the onset of symptoms and for the following 2 days. The results showed no difference in the duration or severity of cold symptoms among the groups. High-dose vitamin C taken at the onset of a cold, in other words, didn't help. A review of 7 randomized and non-randomized trials also found that taking vitamin C at the start of a cold did not offer any benefits.185 The bottom line: If you want to use vitamin C to take the edge off your colds, take the supplement throughout the winter.
There are numerous other natural treatments for the common cold as well, some of which may be more helpful than vitamin C. For more information, see the full Colds and Flus article.
Although two relatively recent studies suggest that regular use of vitamin C throughout the cold season can help prevent colds,167-168 they suffer from a variety of flaws, and most other studies have found little to no benefit along these lines.146
However, people who are truly vitamin C-deficient, such as elderly people in nursing homes, may show increased resistance to infection if they take vitamin C (or other nutrients).86
In addition, vitamin C might be helpful for preventing the respiratory infections that can follow heavy endurance exercise. Marathon running and similar forms of exertion can temporarily weaken the immune system, leading to infections. Vitamin C may be helpful. According to a double-blind, placebo-controlled study involving 92 runners, taking 600 mg of vitamin C for 21 days prior to a race, made a significant difference in the incidence of sickness afterwards.87 Within 2 weeks of the race, 68% of the runners taking placebo developed cold symptoms versus only 33% of those taking the vitamin C supplement. As part of the same study, non-runners of similar age and gender to those running were also given vitamin C or placebo. Interestingly, the supplement had no apparent effect on the incidence of upper respiratory infections in this group. Vitamin C seemed to be effective in this capacity only for those who exercised intensively!
Two other studies found that vitamin C could reduce the number of colds experienced by groups of people involved in rigorous exercise in extremely cold environments.88 One study involved 139 children attending a skiing camp in the Swiss Alps, while the other enrolled 56 military men engaged in a training exercise in northern Canada during the winter months. In both cases, the participants took either 1 g of vitamin C or placebo daily at the time their training program began. Cold symptoms were monitored for 1 to 2 weeks following training, and significant differences in favor of vitamin C were found.
However, one very large study of 674 US Marine recruits in basic training found no such benefit.89 The results showed no difference in the number of colds between the treatment and placebo groups.
What's the explanation for this discrepancy? There are many possibilities. Perhaps basic training in the Marines is significantly different from the other forms of exercise studied. Another point to consider is that the Marines didn't start taking vitamin C right at the beginning of training, but waited 3 weeks. The study also lasted a bit longer than the positive studies mentioned above, continuing for 2 months; maybe vitamin C is more effective at preventing colds in the short term. Of course, another possibility is that it doesn't really work. More research is needed to know for sure.
Preeclampsia is a dangerous complication of pregnancy that involves high blood pressure, swelling of the whole body, and improper kidney function. A double-blind, placebo-controlled study of 283 women at increased risk for preeclampsia found that supplementation with vitamin C (1,000 mg daily) and vitamin E (400 IU daily) significantly reduced the chances of developing this disease.96
While this research is promising, larger studies are necessary to confirm whether vitamins C and E will actually work. The authors of this study point out that similarly sized studies found benefits with other treatments, such as aspirin, that later proved to be ineffective when large-scale studies were performed. Furthermore, keep in mind that we don't know whether such high dosages of these vitamins are absolutely safe for pregnant women.
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.
Reflex sympathetic dystrophy (RSD) is a set of symptoms that can develop in the legs, arms, feet, and hands after fractures and other injuries. Also called complex regional pain syndrome (CRPS), symptoms include changes in skin temperature and color over the affected area, accompanied by burning pain, sensitivity to touch, sweating, and limitation of range of motion. The cause of RSD is unknown, and the condition is very difficult to treat.
Two studies performed by a single research group reported evidence that vitamin C can help prevent RSD after wrist fractures.110,180
In one of these, a total of 123 adults with wrist fractures were enrolled and followed for one year.110 All were given 500 mg of vitamin C or placebo daily for 50 days. The results showed significantly fewer cases of RSD in the treated group.
A subsequent study conducted by the same research group compared placebo against three dosages of vitamin C in 416 people suffering from wrist fracture.180 Again, treatment continued for 50 days. The results indicated that approximately 10% of those given placebo developed RSD, while less than 2% of those given either 500 mg or 1,500 mg of vitamin C daily did so. According to the statistical analysis used by the authors, this relative benefit was statistically significant. The 200 mg dose of vitamin C did appear to offer some protection too, but not as much.
According to a 30-day, double-blind study of 39 individuals taking medications for hypertension, treatment with 500 mg of vitamin C daily can reduce blood pressure by about 10%.112 Smaller benefits were seen in studies of individuals with normal blood pressure or borderline hypertension.113,114,148 However, other studies have failed to find any significant blood pressure-lowering effect.115,116,147 This mixed evidence suggests, on balance, that if vitamin C does have any blood pressure-lowering effect, it is at most quite small.
Nitroglycerin and related nitrate medications are used for the treatment of angina. However, the effectiveness of these medications tends to diminish over time. According to a double-blind study of 48 individuals, use of vitamin C at a dose of 2,000 mg 3 times daily helped maintain the effectiveness of nitroglycerin.142 These findings are supported by other studies as well.143-145
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.
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:
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.129,130,163 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.131-133 Still, there may be certain individuals who are particularly at risk for vitamin C-induced kidney stones.134 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.121-128,164 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.135 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.
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.165
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
The maximum safe dosages of vitamin C for people with severe liver or kidney disease have not been determined.
If you are taking:
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.
1. Lykkesfeldt J, Christen S, Wallock LM, et al. Ascorbate is depleted by smoking and repleted by moderate supplementation: a study in male smokers and nonsmokers with matched dietary antioxidant intakes. Am J Clin Nutr. 2000;71:530-536.
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.
3. Lowik MR, Wedel M, Kistemaker C, et al. Assessment of the adequacy of vitamin C intake in the Netherlands [abstract]. J Am Coll Nutr. 1991;10:544.
4. US Department of Agriculture. National Food Consumption Survey. 1985.
5. Baker B. Vitamin C deficiency common in hospitalized. Fam Pract News. March 1995:25.
6. Taylor CA, Hampl JS, Johnston CS. Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults. Eur J Clin Nutr. 2000;54:573-578.
7. Taylor CA, Hampl JS, Johnston CS. Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults. Eur J Clin Nutr. 2000;54:573-578.
8. Coffey G, Wilson SW. Letter: Ascorbic acid deficiency and aspirin-induced haematemesis. Br Med J. 1975;1:208.
9. Das N, Nebioglu S. Vitamin C aspirin interactions in laboratory animals. J Clin Pharm Ther. 1992;17:343-346.
10. Molloy TP, Wilson CW. Protein-binding of ascorbic acid. 2. Interaction with acetylsalicylic acid. Int J Vit Nutr Res. 1980;50:387-392.
11. Rivers JM, Devine MM. Plasma ascorbic acid concentrations and oral contraceptives. Am J Clin Nutr. 1972;25:684-689.
12. Webb JL. Nutritional effects of oral contraceptive use: a review. J Reprod Med. 1980;25:150-156.
13. Larsson-Cohn U. Oral contraceptives and vitamins: a review. Am J Obstet Gynecol. 1975;121:84-90.
14. Wynn V. Vitamins and oral contraceptive use. Lancet. 1975;1:561-564.
15. Briggs M, Briggs M. Vitamin C requirements and oral contraceptives [letter]. Nature. 1972;238:277.
16. Blanchard J, Tozer TN, Rowland M. Pharmacokinetic perspective on megadoses of ascorbic acid. Am J Clin Nutr. 1997;66:1165-1171.
17. Hemila H. Does vitamin C alleviate symptoms of the common cold? A review of current evidence. Scand J Infect Dis. 1994;26:1-6.
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.
29. 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.
30. Bielory L, Gandhi R. Asthma and vitamin C. Ann Allergy. 1994;73:89-99.
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.
36. Jakeman P, Maxwell S. Effect of antioxidant vitamin supplementation on muscle function after eccentric exercise. Eur J Appl Physiol Occup Physiol. 1993;67:426-430.
37. Taylor TV, Rimmer S, Day B, et al. Ascorbic acid supplementation in the treatment of pressure-sores. Lancet. 1974;2:544-546.
38. Dawson EB, Harris WA, Rankin WE, et al. Effect of ascorbic acid on male fertility. Ann N Y Acad Sci. 1987;498:312-323.
39. Rolf C, Cooper TG, Yeung CH, et al. Antioxidant treatment of patients with asthenozoospermia or moderate oligoasthenozoospermia with high-dose vitamin C and vitamin E: a randomized, placebo-controlled, double-blind study. Hum Reprod. 1999;14:1028-1033.
40. Dolske MC, Spollen J, McKay S, et al. A preliminary trial of ascorbic acid as supplemental therapy for autism. Prog Neuropsychopharmacol Biol Psychiatry. 1993;5:765-774.
41. Miller MJ. Injuries to athletes. Med Times. 1960;88:313-316.
42. Darr D, Combs S, Dunston S, et al. Topical vitamin C protects porcine skin from ultraviolet radiation-induced damage. Br J Dermatol. 1992;127:247-253.
43. Darr D, Dunston S, Faust H, et al. Effectiveness of antioxidants (vitamin C and E) with and without sunscreens as topical photoprotectants. Acta Derm Venereol. 1996;76:264-268.
44. Trevithick JR, Shum DT, Redae S, et al. Reduction of sunburn damage to skin by topical application of vitamin E acetate following exposure to ultraviolet B radiation: effect of delaying application or of reducing concentration of vitamin E acetate applied. Scanning Microsc. 1993;7:1269-1281.
45. Trevithick JR, Xiong H, Lee S, et al. Topical tocopherol acetate reduces post-UVB, sunburn-associated erythema, edema, and skin sensitivity in hairless mice. Arch Biochem Biophys. 1992;296:575-582.
46. Eberlein-Konig B, Placzek M, Przybilla B. Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). J Am Acad Dermatol. 1998;38:45-48.
47. Fuchs J, Kern H. Modulation of UV-light-induced skin inflammation by D-alpha-tocopherol and L-ascorbic acid: a clinical study using solar simulated radiation. Free Radic Biol Med. 1998;25:1006-1012.
48. Werninghaus K, Meydani M, Bhawan J, et al. Evaluation of the photoprotective effect of oral vitamin E supplementation. Arch Dermatol. 1994;130:1257-1261.
49. Fuchs J, Kern H. Modulation of UV-light-induced skin inflammation by D-alpha-tocopherol and L-ascorbic acid: a clinical study using solar simulated radiation. Free Radic Biol Med. 1998;25:1006-1012.
50. Traikovich SS. Use of topical ascorbic acid and its effects on photodamaged skin topography. Arch Otolaryngol Head Neck Surg. 1999;125:1091-1098.
51. Rougier A, Humbert P, Zahouani H, et al. Clinical and biological effects of topical vitamin C in the treatment of skin aging. Presented at: 2nd World Congress of the International Academy of Cosmetic Dermatology; November 9-11, 2000; Rio de Janeiro, Brazil.
52. van Rooij J, Schwartzenberg SGWS, Mulder PGH, et al. Oral vitamins C and E as additional treatment in patients with acute anterior uveitis: a randomised double masked study in 145 patients. Br J Ophthalmol. 1999;83:1277-1282.
53. Simon JA, Hudes ES. Serum ascorbic acid and gallbladder disease prevalence among US adults. Arch Intern Med. 2000;160:931-936.
54. Masaki KH, Losonczy KG, Izmirlian G, et al. Association of vitamin E and C supplement use with cognitive function and dementia in elderly men. Neurology. 2000;54:1265-1272.
55. Raitakari OT, Adams MR, McCredie RJ, et al. Oral vitamin C and endothelial function in smokers: short-term improvement, but no sustained beneficial effect. J Am Coll Cardiol. 2000;35:1616-1621.
56. Bucca C, Rolla G, Oliva A, et al. Effect of vitamin C on histamine bronchial responsiveness of patients with allergic rhinitis. Ann Allergy. 1990;65:311-314.
57. Bellioni P, Artuso A, Di Luzio Parparatti U, et al. Histaminic provocation in allergy. The role of ascorbic acid [in Italian]. Riv Eur Sci Med Farmacol. 1987;9:419-422.
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.
59. McAlindon TE, Jacques P, Zhang Y, et al. Do antioxidant micronutrients protect against the development and progression of knee osteoarthritis? Arthritis Rheum. 1996;39:648-656.
60. Schwartz ER. The modulation of osteoarthritic development by vitamins C and E. Int J Vitam Nutr Res Suppl. 1984;26:141-146.
61. Khaw KT, Bingham S, Welch A, et al. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. Lancet. 2001;357:657-663.
62. Shibata A, Paganini-Hill A, Ross RK, et al. Intake of vegetables, fruits, beta-carotene, vitamin C and vitamin supplements and cancer incidence among the elderly: a prospective study. Br J Cancer. 1992;66:673-679.
63. Cohen M, Bhagavan HN. Ascorbic acid and gastrointestinal cancer. J Am Coll Nutr. 1995;14:565-578.
64. Esteve J, Riboli E, Pequignot G, et al. Diet and cancers of the larynx and hypopharynx: the IARC multi-center study in southwestern Europe. Cancer Causes Control. 1996;7:240-252.
65. Flagg EW, Coates RJ, Greenberg RS. Epidemiologic studies of antioxidants and cancer in humans. J Am Coll Nutr. 1995;14:419-427.
66. Block G. Epidemiologic evidence regarding vitamin C and cancer. Am J Clin Nutr. 1991;54(suppl 6):1310S-1314S.
67. 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.
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.
77. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treat Res. 1997;23:209-240.
78. Weijl NI, Cleton FJ, Osanto S. Free radicals and antioxidants in chemotherapy-induced toxicity. Cancer Treat Res. 1997;23:209-240.
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.
80. Hemila H. Does vitamin C alleviate symptoms of the common cold? A review of current evidence. Scand J Infect Dis. 1994;26:1-6.
81. Hemila H. Vitamin C and the common cold. Br J Nutr. 1992;67:3-16.
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.
124. Lynch SR, Cook JD. Interaction of vitamin C and iron. Ann N Y Acad Sci. 1980;355:32-44.
125. Hunt JR, Gallagher SK, Johnson LK. Effect of ascorbic acid on apparent iron absorption by women with low iron stores. Am J Clin Nutr. 1994;59:1381-1385.
126. Diplock AT. Safety of antioxidant vitamins and beta-carotene. Am J Clin Nutr. 1995;62(suppl 6):1510S-1516S.
127. Hoffman KE, Yanelli K, Bridges KR. Ascorbic acid and iron metabolism: alterations in lysosomal function. Am J Clin Nutr. 1991;54(suppl 6):1188S-1192S.
128. Siegenberg D, Baynes RD, Bothwell TH, et al. Ascorbic acid prevents the dose-dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption. Am J Clin Nutr. 1991;53:537-541.
129. 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.
130. Traxer O, Adams-Huet B, Pak CY, et al. Risk of calcium oxalate stone formation with ascorbic acid ingestion. Presented at: American Urological Association 2001 Annual Meeting; June 2-7, 2001; Anaheim, CA.
131. 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.
132. 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.
133. Simon JA, Hudes ES. Relation of serum ascorbic acid to serum vitamin B12, serum ferritin, and kidney stones in US adults. Arch Intern Med. 1999;159:619-624.
134. 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.
135. Houston JB, Levy G. Drug biotransformation interactions in man VI: acetaminophen and ascorbic acid. J Pharm Sci. 1976;65:1218-1221.
136. Owen CA Jr, Tyce GM, Flock EV, et al. Heparin-ascorbic acid antagonism. Mayo Clin Proc. 1970;45:140-145.
137. Rosenthal G. Interaction of ascorbic acid and warfarin [letter]. JAMA. 1971;215:1671.
138. Harris JE. Interaction of dietary factors with oral anticoagulants: review and applications. J Am Diet Assoc. 1995;95:580-584.
139. Smith EC, Skalski RJ, Johnson GC, et al. Interaction of ascorbic acid and warfarin. JAMA. 1972;221:1166.
140. Audera C, Patulny RV, Sander BH, et al. Mega-dose vitamin C in treatment of the common cold: a randomised controlled trial. Med J Aust. 2001;175:359-362.
141. Blee TH, Cogbill TH, Lambert PJ. Hemorrhage associated with vitamin C deficiency in surgical patients. Surgery. 2002;131:408-412.
142. Watanabe H, Kakihana M, Ohtsuka S, et al. Randomized, double-blind, placebo-controlled study of the preventive effect of supplemental oral vitamin C on attenuation of development of nitrate tolerance. J Am Coll Cardiol. 1998;31:1323-1329.
143. Bassenge E, Fink N, Skatchkov M, et al. Dietary supplement with vitamin C prevents nitrate tolerance. J Clin Invest. 1998;31:67-71.
144. Daniel TA, Nawarskas JJ. Vitamin C in the prevention of nitrate tolerance. Ann Pharmacother. 2000;4:1193-1197.
145. McVeigh GE, Hamilton P, Wilson M, et al. Platelet nitric oxide and superoxide release during the development of nitrate tolerance: effect of supplemental ascorbate. Circulation. 2002;106:208-213.
146. Douglas RM, Chalker EB, Treacy B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2000;CD000980.
147. Kim MK, Sasaki S, Sasazuki S, et al. Lack of long-term effect of vitamin C supplementation on blood pressure. Hypertension. 2002;40:797-803.
148. Mullan BA, Young IS, Fee H, et al. Ascorbic Acid reduces blood pressure and arterial stiffness in type 2 diabetes. Hypertension. 2002;40:804-809.
149. Baxter RC. Vitamin C and glaucoma. J Am Optom Assoc. 1988;59:438.
150. Mavrikakis ME, Lekakis JP, Papamichael CM, et al. Ascorbic acid does not improve endothelium-dependent flow-mediated dilatation of the brachial artery in patients with Raynaud's phenomenon secondary to systemic sclerosis. Int J Vitam Nutr Res. 2003;73:3-7.
151. Drisko JA, Chapman J, Hunter VJ. The use of antioxidant therapies during chemotherapy. Gynecol Oncol. 2003;88:434-439.
152. Padayatty SJ, Sun H, Wang Y, et al. Vitamin C pharmacokinetics: implications for oral and intravenous use. Ann Intern Med. 2004;140:533-537.
153. Hemila H, Virtamo J, Albanes D, Kaprio J. Physical activity and the common cold in men administered vitamin E and beta-carotene. Med Sci Sports Exerc. 2003;35:1815-1820.
154. Harrison SA, Torgerson S, Hayashi P, et al. Vitamin E and vitamin C treatment improves fibrosis in patients with nonalcoholic steatohepatitis. Am J Gastroenterol. 2003;98:2485-2490.
155. Henmi H, Endo T, Kitajima Y, et al. Effects of ascorbic acid supplementation on serum progesterone levels in patients with a luteal phase defect. Fertil Steril. 2003;80:459-461.
156. Casanueva E, Ripoll C, Tolentino M, et al. Vitamin C supplementation to prevent premature rupture of the chorioamniotic membranes: a randomized trial. Am J Clin Nutr. 2005;81:859-863.
157. Humbert PG, Haftek M, Creidi P, et al. Topical ascorbic acid on photoaged skin. Clinical, topographical and ultrastructural evaluation: double-blind study vs. placebo. Exp Dermatol. 2003;12:237-244.
158. Ward NC, Hodgson JM, Croft KD, et al. Effects of vitamin C and grape-seed polyphenols on blood pressure in treated hypertensive individuals: results of a randomised double blind, placebo-controlled trial. Asia Pac J Clin Nutr. 2003;12(suppl):S18.
159. Petersen EE, Magnani P. Efficacy and safety of vitamin C vaginal tablets in the treatment of non-specific vaginitis; A randomised, double blind, placebo-controlled study. Eur J Obstet Gynecol Reprod Biol. 2004;117:70-75.
160. 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.
161. Kim MK, Sasaki S, Sasazuki S, et al. Long-term vitamin C supplementation has no markedly favourable effect on serum lipids in middle-aged Japanese subjects. Br J Nutr. 2004;91:81-90.
162. Douglas R, Hemila H, D'Souza R, et al. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2004;CD000980.
163. Traxer O, Huet B, Poindexter J, et al. Effect of ascorbic acid consumption on urinary stone risk factors. J Urol. 2003;170:397-401.
164. Mallory MA, Sthapanachai C, Kowdley KV. Iron overload related to excessive vitamin C intake. Ann Intern Med. 2003;139:532-533.
165. 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.
166. Seifried HE, McDonald SS, Anderson DE, et al. The antioxidant conundrum in cancer. Cancer Res. 2003;63:4295-4298.
167. Van Straten M, Josling P. Preventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled survey. Adv Ther. 2002;19:151-159.
168. Sasazuki S, Sasaki S, Tsubono Y, et al. Effect of vitamin C on common cold: randomized controlled trial. Eur J Clin Nutr. 2005 Aug 24. [Epub ahead of print]
169. Beazley D, Ahokas R, Livingston J, et al. Vitamin C and E supplementation in women at high risk for preeclampsia: A double-blind, placebo-controlled trial. Am J Obstet Gynecol. 2005;192:520-521.
170. Rumbold AR, Crowther CA, Haslam RR, et al. Vitamins C and E and the risks of preeclampsia and perinatal complications. N Engl J Med. 2006;354:1796-806.
171. Karakilcik AZ, Hayat A, Aydilek N, et al. Effects of vitamin C on liver enzymes and biochemical parameters in rats anesthetized with halothane. Gen Physiol Biophys. 2005;24:47-55.
172. Huang HY, Appel LJ, Choi MJ, et al. The effects of vitamin C supplementation on serum concentrations of uric acid: Results of a randomized controlled trial. Arthritis Rheum. 2005 Jun 2. [Epub ahead of print]
173. Johnston CS, Corte C, Swan PD. Marginal vitamin C status is associated with reduced fat oxidation during submaximal exercise in young adults. Nutr Metab (Lond). 2006 Aug 31. [Epub ahead of print]
174. Naylor GJ, et al. A double blind placebo controlled trial of ascorbic acid in obesity. IRCS J Med Sci. 1982;10:25-28.
175. Naylor GJ, Grant L, Smith C. A double blind placebo controlled trial of ascorbic acid in obesity. Nutr Health. 1985;4:25-28.
176. Bryer SC, Goldfarb AH. Effect of high dose vitamin C supplementation on muscle soreness, damage, function, and oxidative stress to eccentric exercise. Int J Sport Nutr Exerc Metab. 2006;16:270-280.
177. Connolly DA, Lauzon C, Agnew J, et al. The effects of vitamin C supplementation on symptoms of delayed onset muscle soreness. J Sports Med Phys Fitness. 2006;46:462-467.
178. Tecklenburg SL, Mickleborough TD, Fly AD, et al. Ascorbic acid supplementation attenuates exercise-induced bronchoconstriction in patients with asthma. Respir Med. 2007 Apr 4. [Epub ahead of print]
179. Chuang CH, Sheu BS, Kao AW, et al. Adjuvant effect of vitamin C on omeprazole-amoxicillin-clarithromycin triple therapy for Helicobacter pylori eradication. Hepatogastroenterology. 2007;54:320-324.
180. Zollinger PE, Tuinebreijer WE, Breederveld RS, et al. Can vitamin C prevent complex regional pain syndrome in patients with wrist fractures? A randomized, controlled, multicenter dose-response study. J Bone Joint Surg Am. 2007;89:1424-1431.
181. Cook NR, Albert CM, Gaziano JM, et al. A randomized factorial trial of vitamins C and E and beta carotene in the secondary prevention of cardiovascular events in women: results from the Women's Antioxidant Cardiovascular Study. Arch Intern Med. 2007;167:1610-1618.
182. Eslami M, Badkoubeh RS, Mousavi M, et al. Oral ascorbic acid in combination with beta-blockers is more effective than beta-blockers alone in the prevention of atrial fibrillation after coronary artery bypass grafting. Tex Heart Inst J. 2007;34:268-274.
183. Sesso HD, Buring JE, Christen WG, et al. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. JAMA. 2008;300:2123-2133.
184. Khajehei M, Keshavarz T, Tabatabaee HR. Randomised double-blind trial of the effect of vitamin C on dyspareunia and vaginal discharge in women receiving doxycycline and triple sulfa for chlamydial cervicitis. Aust N Z J Obstet Gynaecol. 2009;49:525.
185. Hemila H, Chalker E, Douglas B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2010;(3):CD000980.
186. Christen WG, Glynn RJ, Sesso HD, et al. Age-related cataract in a randomized trial of vitamins E and C in men. Arch Ophthalmol. 2010;128(11):1397-1405.
187. Hemilä H, Louhiala P. Vitamin C for preventing and treating pneumonia. Cochrane Database Syst Rev. 2007;(1):CD005532.
188. Dietary supplement fact sheet: vitamin C. Office of Dietary Supplements website. Available at: http://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/. Accessed September 10, 2012.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2015