Life Extension Final Clerance Sale

Abstracts

ABSTRACTS FOR THE VITAMIN C CONTROVERSY

101. Male infertility: nutritional and environmental considerations.

Altern Med Rev 2000 Feb;5(1):28-38
Sinclair S
Green Valley Health, Hagerstown, MD 21742, USA.

Studies confirm that male sperm counts are declining, and environmental factors, such as pesticides, exogenous estrogens, and heavy metals may negatively impact spermatogenesis. A number of nutritional therapies have been shown to improve sperm counts and sperm motility, including carnitine, arginine, zinc, selenium, and vitamin B-12. Numerous antioxidants have also proven beneficial in treating male infertility, such as vitamin C, vitamin E, glutathione, and coenzyme Q10. Acupuncture, as well as specific botanical medicines, have been documented in several studies as having a positive effect on sperm parameters. A multi-faceted therapeutic approach to improving male fertility involves identifying harmful environmental and occupational risk factors, while correcting underlying nutritional imbalances to encourage optimal sperm production and function. (The following are excepts from this study:)
"Studies have shown the concentration of ascorbic acid in seminal plasma directly reflects dietary intake, and lower levels of vitamin C may lead to infertility and increased damage to the sperm's genetic material.36 Fraga et al demonstrated this by reducing ascorbic acid intake in healthy men from 250 mg to 5 mg per day. Seminal plasma levels of vitamin C decreased by 50 percent, with a concomitant 91-percent increase in sperm with DNA damage.37 Cigarette smoking has been documented as having deleterious effects on sperm quality. In a University of Texas study on vitamin C and sperm quality in heavy smokers, 75 men were divided into three supplementation groups; one was given placebo, the other groups received 200 mg or 1000 mg ascorbic acid. While the placebo group showed no improvement, the ascorbic acid groups showed significant improvement in sperm quality, with the greatest improvement occurring in the 1000 mg group.38 In perhaps one of the best studies on vitamin C and male infertility, 30 infertile but otherwise healthy men were given a placebo, 200 mg, or 1000 mg vitamin C daily. After one week, the group receiving 1000 mg/day had a 140-percent increase in sperm count, while there was no change in the placebo group. The 200 mg/day group had a 112-percent increase in sperm count, while both groups demonstrated significant reductions in the number of agglutinated sperm. Most importantly, by the end of the 60-day study every participant in the vitamin C group had impregnated their partner, while no pregnancies occurred in the placebo group"


102. 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 Nov;83(11):1277-82
van Rooij J, Schwartzenberg SG, Mulder PG, Baarsma SG
Eye Hospital Rotterdam, Rotterdam, Netherlands.

AIM: To investigate the effect of additional oral vitamins C and E on acute anterior uveitis. METHODS: A placebo controlled double masked study on the effect of vitamin C 500 mg in combination with vitamin E 100 mg twice daily in 145 patients with acute anterior uveitis. As a primary end point variable, laser cell/flare measurements were performed. Best corrected and stenopeic visual acuity (VA) testing and clinical variable scores were measured. RESULTS: Laser flare measurements (ph/s) before treatment were 207.1 (SD 258) in the vitamin group and 143.6 (156) in the placebo group. After 3 days corresponding values were 80.2 (129) and 54.7 (82), after 7 days 89.2 (187) (12.5) and 85.8 (208), after 14 days 47.1 (109.5) and 40.5 (116) after 28 days 23.1 (53.6) and 23.1 (48), and after 56 days 15.6 (26) and 15.3 (17). There was no significant difference in time trend between the two treatment groups (RMANOVA; p = 0.53). Baseline VA (logMAR) was 0.106 (0.241) in the vitamin group and 0.128 (0.456) in the placebo group. VA after 3 days was 0. 236 (0.293) and 0.344 ( 0.489), after 7 days 0.204 (0.292) and 0.292 (0.479), after 14 days 0.162 (0.274) and 0.193 (0.454), after 28 days 0.096 (0.232) and 0.158 (0.436), and 0.026 (0.213) and 0.106 (0. 437) after 56 days. Although no significant difference in time trend was detected, evaluation of the VA data of the last time point (56 days) by means of the Mann-Whitney test showed a significantly better VA in the vitamin group (p = 0.01). CONCLUSIONS: There was no significant effect of vitamins C and E on laser flare measurements. The significant effect of the oral vitamins on visual acuity at 8 weeks after start of the oral vitamins C and E may indicate a protective effect in patients with acute anterior uveitis.


103. Effect of vitamin C on frequency of reflex sympathetic dystrophy in wrist fractures: a randomised trial.

Lancet 1999 Dec 11;354(9195):2025-8
Zollinger PE, Tuinebreijer WE, Kreis RW, Breederveld RS
Department of Orthopaedics, Leyenburg Hospital, The Hague, The Netherlands.

BACKGROUND: The pathogenesis of reflex sympathetic dystrophy (RSD) is not clear, nor is there a definitive treatment for this syndrome. The morbidity, costs in health care, and loss of work time justify the search for a means to prevent post-traumatic dystrophy. Although the role of toxic oxygen radicals has not yet been clarified, we investigated vitamin C (ascorbic acid) as a prophylactic antioxidant drug. METHODS: 123 adults with 127 conservatively treated wrist fractures were randomly allocated in a double-blind trial to take a capsule of 500 mg vitamin C or placebo daily for 50 days. Each participant's sex, age, side of fracture, dominance, fracture type, dislocation, reduction, and complaints with the plaster cast were recorded, and they were clinically scored for RSD. The follow-up lasted 1 year. FINDINGS: Eight patients were withdrawn after randomisation. 52 patients with 54 fractures (male 22%, female 78%; mean age 57 years) received vitamin C and 63 patients with 65 fractures (male 20%, female 80%; mean age 60 years) received placebo. RSD occurred in four (7%) wrists in the vitamin C group and 14 (22%) in the placebo group 15% (95% CI for differences 2-26). Other significant prognostic variables for the occurrence of RSD were complaints while wearing the cast (relative risk 0.17 [0.07-0.41]) and fracture type (0.37 [0.16-0.89]). INTERPRETATION: This prospective, double-blind study shows that vitamin C was associated with a lower risk of RSD after wrist fractures. Our hypothesis is that this beneficial effect of prophylaxis would be useful in other forms of trauma.


104. The effectiveness of vitamin C in preventing and relieving the symptoms of virus-induced respiratory infections.

J Manipulative Physiol Ther 1999 Oct;22(8):530-3
Gorton HC, Jarvis K

BACKGROUND: An ever increasing demand to evaluate the effect of dietary supplements on specific health conditions by use of a "significant scientific" standard has prompted the publication of this study. OBJECTIVE: To study the effect of megadose Vitamin C in preventing and relieving cold and flu symptoms in a test group compared with a control group. DESIGN: Prospective, controlled study of students in a technical training facility. SUBJECTS: A total of 463 students ranging in age from 18 to 32 years made up the control group. A total of 252 students ranging in age from 18 to 30 years made up the experimental or test group. METHOD: Investigators tracked the number of reports of cold and flu symptoms among the 1991 test population of the facility compared with the reports of like symptoms among the 1990 control population. Those in the control population reporting symptoms were treated with pain relievers and decongestants, whereas those in the test population reporting symptoms were treated with hourly doses of 1000 mg of Vitamin C for the first 6 hours and then 3 times daily thereafter. Those not reporting symptoms in the test group were also administered 1000-mg doses 3 times daily. RESULTS: Overall, reported flu and cold symptoms in the test group decreased 85% compared with the control group after the administration of megadose Vitamin C. CONCLUSION: Vitamin C in megadoses administered before or after the appearance of cold and flu symptoms relieved and prevented the symptoms in the test population compared with the control group.


105. Effect of ascorbic acid and green tea on endogenous formation of N-nitrosodimethylamine and N-nitrosopiperidine in humans.

Mutat Res 1999 Jul 16;428(1-2):353-61
Vermeer IT, Moonen EJ, Dallinga JW, Kleinjans JC, van Maanen JM
Department of Health Risk Analysis and Toxicology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, Netherlands.
i.vermeer@grat.unimaas.nl

Many constituents present in the human diet may inhibit endogenous formation of N-nitroso compounds (NOC). Studies with human volunteers showed inhibiting effects of intake of ascorbic acid and green tea consumption on nitrosation using the N-nitrosoproline test. The aim of the present study was to evaluate the effects of ascorbic acid and green tea on urinary excretion of carcinogenic N-nitrosodimethylamine (NDMA) and N-nitrosopiperidine (NPIP) in humans. Twenty-five healthy female volunteers consumed a fish meal rich in amines as nitrosatable precursors in combination with intake of nitrate-containing drinking water at the Acceptable Daily Intake level during 7 consecutive days. During 1 week before and after nitrate intake a diet low in nitrate was consumed. Using the same protocol, the effect of two different doses of ascorbic acid (250 mg and 1 g/day) and two different doses of green tea (2 g and 4 g/day) on formation of NDMA and NPIP was studied. Mean nitrate excretion in urine significantly increased from control (76+/-24) to 167+/-25 mg/24 h. Intake of nitrate and fish resulted in a significant increase in mean urinary excretion of NDMA compared with the control weeks: 871+/-430 and 640+/-277 ng/24 h during days 1-3 and 4-7, respectively, compared with 385+/-196 ng/24 h (p<0.0002). Excretion of NPIP in urine was not related to nitrate intake and composition of the diet. Intake of 250 mg and 1 g of ascorbic acid per day resulted in a significant decrease in urinary NDMA excretion during days 4-7 (p=0.0001), but not during days 1-3. Also, consumption of four cups of green tea per day (2 g) significantly decreased excretion of NDMA during days 4-7 (p=0.0035), but not during days 1-3. Surprisingly, consumption of eight cups of green tea per day (4 g) significantly increased NDMA excretion during days 4-7 (p=0.0001), again not during days 1-3. This increase is probably a result of catalytic effects of tea polyphenols on nitrosation, or of another, yet unknown, mechanism. These results suggest that intake of ascorbic acid and moderate consumption of green tea can reduce endogenous NDMA formation.


106. Treatment of progressive pigmented purpura with oral bioflavonoids and ascorbic acid: an open pilot study in 3 patients.

J Am Acad Dermatol 1999 Aug;41(2 Pt 1):207-8
Reinhold U, Seiter S, Ugurel S, Tilgen W
Department of Dermatology, The Saarland University Hospital, Homburg/Saar, Germany.

BACKGROUND: Bioflavonoids and ascorbic acid have been shown to increase capillary resistance and to mediate potent antioxidative radical scavenging activities. OBJECTIVE: We evaluated the clinical effect of oral bioflavonoids and ascorbic acid in patients with chronic progressive pigmented purpura (PPP). METHODS: In an open pilot study, oral rutoside (50 mg twice a day) and ascorbic acid (500 mg twice a day) were administered to 3 patients with chronic PPP. RESULTS: At the end of the 4-week treatment period, complete clearance of the skin lesions was achieved in all 3 patients. No adverse reactions were noted. All patients remained free of lesions at the end of 3 months after treatment. CONCLUSION: Our results suggest a beneficial effect of bioflavonoids in combination with ascorbic acid on PPP. Because the disease is mostly resistant to other treatment modalities, placebo-controlled studies are necessary to determine the usefulness of this therapy in PPP.


107. Vitamin C supplementation and common cold symptoms: factors affecting the magnitude of the benefit.

Med Hypotheses 1999 Feb;52(2):171-8
Hemila H
Department of Public Health, University of Helsinki, Finland.

Placebo-controlled trials have shown that vitamin C supplementation decreases the duration and severity of common cold infections. However, the magnitude of the benefit has substantially varied, hampering conclusions about the clinical significance of the vitamin. In this paper, 23 studies with regular vitamin C supplementation (> or = 1 g/day) were analyzed to find out factors that may explain some part of the variation in the results. It was found that on average, vitamin C produces greater benefit for children than for adults. The dose may also affect the magnitude of the benefit, there being on average greater benefit from > or = 2 g/day compared to 1 g/day of the vitamin. In five studies with adults administered 1 g/day of vitamin C, the median decrease in cold duration was only 6%, whereas in two studies with children administered 2 g/day the median decrease was four times higher, 26%. The trials analyzed in this work used regular vitamin C supplementation, but it is conceivable that therapeutic supplementation starting early at the onset of the cold episode could produce comparable benefits. Since few trials have examined the effects of therapeutic supplementation and their results have been variable, further therapeutic trials are required to examine the role of vitamin C in the treatment of colds.


108. Intake of vitamins B6 and C and the risk of kidney stones in women.

J Am Soc Nephrol 1999 Apr;10(4):840-5
Curhan GC, Willett WC, Speizer FE, Stampfer MJ|Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
gary.curhan@channing.harvard.edu

Urinary oxalate is an important determinant of calcium oxalate kidney stone formation. High doses of vitamin B6 may decrease oxalate production, whereas vitamin C can be metabolized to oxalate. This study was conducted to examine the association between the intakes of vitamins B6 and C and risk of kidney stone formation in women. The relation between the intake of vitamins B6 and C and the risk of symptomatic kidney stones were prospectively studied in a cohort of 85,557 women with no history of kidney stones. Semiquantitative food-frequency questionnaires were used to assess vitamin consumption from both foods and supplements. A total of 1078 incident cases of kidney stones was documented during the 14-yr follow-up period. A high intake of vitamin B6 was inversely associated with risk of stone formation. After adjusting for other dietary factors, the relative risk of incident stone formation for women in the highest category of B6 intake (> or =40 mg/d) compared with the lowest category (<3 mg/d) was 0.66 (95% confidence interval, 0.44 to 0.98). In contrast, vitamin C intake was not associated with risk. The multivariate relative risk for women in the highest category of vitamin C intake (> or =1500 mg/d) compared with the lowest category (<250 mg/d) was 1.06 (95% confidence interval, 0.69 to 1.64). Large doses of vitamin B6 may reduce the risk of kidney stone formation in women. Routine restriction of vitamin C to prevent stone formation appears unwarranted.


109. Biomarkers for establishing a tolerable upper intake level for vitamin C
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Nutr Rev 1999 Mar;57(3):71-7
Johnston CS
Foods and Nutrition Laboratories, Arizona State University, Tempe 85287-2502, USA.

Dietary reference intakes (DRIs) for vitamin C for healthy U.S. populations are currently being formulated by the Panel on Dietary Antioxidants and Related Compounds of the Food and Nutrition Board of the Institute of Medicine. A major task of the Panel is to analyze the evidence of adverse effects of high-dose vitamin C intakes to derive, if appropriate, a Tolerable Upper Intake Level (UL) for vitamin C. The present report details current and past research examining potential adverse effects of supplemental vitamin C. The available data indicate that very high intakes of vitamin C (2-4 g/day) are well tolerated biologically in healthy mammalian systems. Currently, strong scientific evidence to define and defend a UL for vitamin C is not available.


110. Effects of high dose vitamin C treatment on Helicobacter pylori infection and total vitamin C concentration in gastric juice.

Eur J Cancer Prev 1998 Dec;7(6):449-54
Jarosz M, Dzieniszewski J, Dabrowska-Ufniarz E, Wartanowicz M, Ziemlanski S, Reed PI
Department of Metabolic Diseases and Gastroenterology, National Food and Nutrition Institute (WHO Collaborating Centre for Nutrition), Warsaw, Poland.

Low gastric juice total vitamin C concentration in the presence of Helicobacter pylori (H. pylori) infection probably plays a role in gastric carcinogenesis. In vitro vitamin C has been shown to inhibit the growth of H. pylori. The aims of this study were to determine the effect of high dose vitamin C administration on H. pylori infection and on gastric juice total vitamin C concentration in patients with H. pylori related chronic gastritis. Sixty patients with dyspeptic symptoms and proven chronic gastritis and H. pylori infection, who were undergoing routine endoscopy, entered the study after giving informed consent. They were randomly coded into two treatment groups. Group 1 (controls, n = 28) were treated with antacids for 4 weeks and Group 2 (n = 32) received vitamin C 5g daily also for 4 weeks. Nine patients did not complete the study and were excluded. Plasma and gastric juice total vitamin C levels were measured at baseline, at the end of 4 weeks treatment and again 4 weeks after treatment cessation. In the control group H. pylori infection remained unchanged in all 24 patients throughout as did the mean gastric juice total vitamin C concentration. However, in the vitamin C treated group eight of 27 patients (30%) who completed the treatment course the H. pylori infection was eradicated (P = 0.01). In these patients the mean gastric juice total vitamin C concentration rose significantly from 7.2 +/- 1.6 micrograms/ml after 4 weeks treatment (P < M 0.001) and 19.8 micrograms/ml 4 weeks after treatment was discontinued (P < 0.001). In the remaining 19 patients with persistent H. pylori infection, the mean gastric juice total vitamin C concentration rose less than in those with successful H. pylori eradication; 6.3 +/- 1.7 micrograms/ml before treatment, 10.8 +/- 1.5 micrograms/ml after 4 weeks treatment (P < 0.05) and a return to pre-treatment levels (7.1 +/- 2.7 micrograms/ml) 4 weeks after vitamin C intake stopped. There were no side effects of vitamin C treatment. This study has shown that 4 weeks daily high dose vitamin C treatment in H. pylori infected patients with chronic gastritis resulted in apparent H. pylori eradication in 30% of those treated. In those patients there was also a highly significant rise in gastric juice total vitamin C concentration which persisted for at least 4 weeks after the treatment ceased. A significant, though less marked, gastric juice total vitamin C concentration increase was observed during vitamin C treatment even in subjects with persistent H. pylori infection, though this was not maintained after treatment ended. The mechanism whereby vitamin C treatment appeared to result in H. pylori eradication is unclear. Further confirmatory studies are indicated.