Last Updated:
Mon Jul 1 08:35:33 CDT 2002
Submitted by Bill Sardi
Linus Pauling was a mentor of mine and a sponsor of the Center for Vitamins
and Cancer Research that I co-founded at the University of Colorado Medical
School in 1980. He was a great supporter of Vitamin C for all that ails
you. There are many recent research papers showing reduction in heart
disease, increased longevity, and so forth from taking more than 10 times
the government recommended amount of Vitamin C. One of the arguments
against taking large amount of Vitamin C was the risk of kidney stones.
That debate has been laid to rest by a large study showing no increase
in kidney stones from Vitamin C and a significant reduction in kidney
stones from increased Vitamin B6.
posted by Jeff
Sutherland @ 8:45 AM
http://www.jeffsutherland.org/complementary/
See also: "Why Don't Massive Doses of Ascorbate Produce Kidney
Stones?" @:
http://www.orthomed.com/kidneyst.htm
Submitted by Chris Gupta
Contributed by Bill Sardi
Here we see a report that confirms that circulating vitamin C levels differ from tissue levels. The eye has greater need for antioxidants due to its transparent nature and bombardment by solar ultraviolet radiation. In this report, there was no systemic shortage of vitamin C, but there was a shortage in the retinal tissues. Bill SardiInt J Vitam Nutr Res 2002 Mar;72(2):63-70
Ohta Y, Okubo T, Niwa T, Yamasaki T, Horiguchi M.
Department of Chemistry, School of Medicine, Fujita Health University, Toyoake, Aichi 470-1192, Japan. yohta@fujita-hu.ac.jp
We examined whether prolonged marginal ascorbic acid deficiency induces oxidative stress in the retina of guinea pigs. Male guinea pigs aged four weeks were given a scorbutic diet (20 g/animal per day) with either marginally deficient ascorbic acid (0.5 mg/animal per day) or adequate ascorbic acid (1 g/animal per day) in drinking water for three and six months. The retinal contents of the reduced form of ascorbic acid in the deficient group at three and six months were 68.1 and 43.5%, respectively, of that in the corresponding adequate group. The retinal contents of the oxidized form of ascorbic acid in the deficient group at three and six months were 1.9- and 2.7-fold, respectively, higher than that in the corresponding adequate group. The content of retinal thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation, in the deficient group was 2.5-fold higher than that in the adequate group at six months. The retinal contents of reduced glutathione (GSH) in the deficient group at three and six months were 84.8 and 66.7%, respectively, of that in the corresponding adequate group. The deficient group had 37.5% of retinal vitamin E content of the adequate group at six months. The deficient group had higher serum vitamin E concentration than the adequate group in both experimental periods. There were no differences in serum TBARS and GSH concentrations between the groups at both periods. These results indicate that prolonged marginal ascorbic acid deficiency induces oxidative stress in the retina of guinea pigs without systemic oxidative stress.
Sibulesky L, Hayes KC, Pronczuk A, Weigel-DiFranco C, Rosner B, Berson EL.
BACKGROUND: Vitamin A supplementation is being used successfully to treat some forms of cancer and the degenerative eye disease retinitis pigmentosa. The daily biological need for vitamin A is estimated to be 800 retinol equivalents (RE)/d (2667 IU/d) for adult women and 1000 RE/d (3300 IU/d) for adult men; doses > or = 7500 RE (> or = 25000 IU)/d are considered potentially toxic over the long term.
OBJECTIVE: We assessed the safety in adults of long-term vitamin A supplementation with doses above the daily biological need but <7500 RE (< 25000 IU)/d.
DESIGN: Adults aged 18-54 y with retinitis pigmentosa but in generally good health (n = 146) were supplemented with 4500 RE (15000 IU) vitamin A/d for < or = 12 y (group A) and compared with a similar group (n = 149) that received 23 RE (75 IU)/d (trace group). Mean total consumption of vitamin A in group A was 5583 RE (18609 IU)/d (range: 4911-7296 RE/d, or 16369-24318 IU/d) and that in the trace group was 1053 RE (3511 IU)/d (range: 401-3192 RE/d, or 1338-10638 IU/d).
RESULTS: Patients in group A showed an 8% increase in mean serum retinol concentration at 5 y and an 18% increase at 12 y (P < 0.001); no retinol value exceeded the upper normal limit (3.49 micromol/L, or 100 microg/dL). Mean serum retinyl esters were elevated approximately 1.7-fold at 5 y and remained relatively stable thereafter. No clinical symptoms or signs of liver toxicity attributable to vitamin A excess were detected.
CONCLUSIONS: Prolonged daily consumption of <7500 RE (<25000 IU) vitamin A/d can be considered safe in this age group.
Foster Biomedical Research Laboratory, Brandeis University, Waltham, MA, USA.
In regards to toxicity symptoms from vitamin A, that would be very rare for people who are healthy. For people with pre-existing liver disease, yes excessive vitamin A may be problematic, but it is the liver that is the problem, not the vitamin A. Yes, they may be hiding the toxic effects of cancer therapy, but if they are treating the liver for cancer then that would make a difference. Vitamin A would be used for epithelial types of cancer like in the stomach, oral, rectal tracts, not brain cancer. The FDA scares people away from high-dose vitamin A. But there are only a few (maybe 30) cases of toxicity annually, while millions are deficient. Those few cases are the people with liver disease. An interesting study was recently conducted among people who are night blind (retinitis pigmentosa) and they were given ~25,000 IU of vitamin A for 5-12 years, with absolutely no toxicity! See above... Bill Sardi
In yet another report demonstrating beta-carotene and vitamin C's protective effects against cancer, the April 2002 Journal of Nutrition (www.nutrition.org) is the site of the publication of a study showing that male smokers who consume more vitamin C and beta-carotene and less iron (typically derived from meat), had a lower risk of mortality from all causes including cancer, compared to those who consumed less of the vitamins and more iron. The Belgian and Dutch researchers interviewed 2,814 male smokers who were part of the Belgian Interuniversity Research on Nutrition and Health study in order to obtain information concerning dietary habits, and participants completed questionnaires that provided their age, educational level and smoking history and frequency. The researchers determined oxidative balance scores, which reflected the balance between antioxidants, in this case beta-carotene and vitamin C, and prooxidants, which in this case was iron. Blood samples were taken and analyzed for serum total cholesterol and HDL cholesterol.
Ten years following the initial examination, the vital status of each participant was determined. Men who had the highest oxidative balance scores, meaning a diet high in iron and low in vitamin C and beta-carotene, had a higher relative risk of all cause mortality and total cancer mortality. When lung cancer mortality was examined, the group consuming the most beta-carotene and vitamin C was found to have a lower incidence of the disease than the other group The benefit of this dietary pattern on cardiovascular disease mortality risk was not considered significant.
Although iron is essential to human life, high iron stores or intake promote free radical formation. This increased oxidative stress can increase DNA damage and the oxidative activation of precarcinogens, supporting tumor cell growth. Because smokers experience increased oxidative damage, increasing their beta-carotene, vitamin C and other antioxidants, and decreasing the consumption of meat, the major source of dietary iron, may help protect against their increased risk of cancer and allow them a longer lifespan. As vitamin C consumption had been positively correlated with lower mortality from all causes in an earlier study, nonsmokers could benefit from this advice as well. LIFE EXTENSION WEEKLY UPDATE EXCLUSIVE
Vitamin C's role in the prevention of disease and malignancy has been studied over the last several decades. Vitamin C intake has been shown to have an inverse relationship with gastric cancer. Recent follow-up studies on high-risk populations suggest that ascorbic acid, the reduced form of vitamin C, protects against gastric cancer, for which H. pylori is a significant risk factor. In populations infected with H. pylori, there is a reduction in gastric juice ascorbic acid concentration. This article reviews the risk factors for gastric cancer and the role of vitamin C in prevention of the disease.
Nutr Rev 2002 Jan;60(1):34-6
Feiz HR, Mobarhan S.
Department of Gastroenterology, Loyola University of Chicago, Maywood, IL 60153, USA.
Contributed by Bill Sardi, Knowledge of Health
When rat liver epithelial cells were treated with vitamin C!
, the researchers report, inhibition of GJIC induced by hydrogen peroxide was prevented.Although vitamin C protects against oxidative DNA damage through its free-radical scavenging activity, Lee and his coworkers believe that the vitamin's anti-tumor action functions through a different mechanism."The most powerful weapon we have in the fight against cancer is prevention," concludes Lee. "A diet rich in phytochemicals and vitamin C will reduce the risk of cancer. These phytochemicals and nutrients are most readily available in fresh fruits and vegetables." These recommendations echo those of Lee and his Cornell colleagues in a report in the journal
Nature (June 22, 2000).Related websites:New York State Agricultural Experiment Station (article and photograph of Lee)The Lancet
[Contact: Linda McCandless]
23-Jan-2002