Vitamin C is one of the most versatile of all vitamins. It is well-known for its important role in skin, joint and bone health. Besides, vitamin C also has anti-carcinogenic, anti-viral, anti-hypertensive, anti-atherogenic, anti-histaminic, immuno-modulatory, ophthalmo-protective and airway-protective actions. It is also necessary for the synthesis of adrenaline and serotonin. Deficiency may cause scurvy. Rich sources are citrus fruits, vegetables (especially peppers), black currant and strawberries. Cooking and heat destroys vitamin C. Recommended daily allowance is 15-125 milligrams based on age and risk factors. (For more detailed information, please visit ISM’s searchable database: Nutraceutical Search.)
Data from several countries in Asia and Latin America indicate that deficiencies of vitamin C and zinc continue to be at alarming levels.……….Overall, there is increasing evidence that deficiency of vitamin C and zinc adversely affects the physical and mental growth of children and can impair their immune defenses.
o Maggini, S, Wenzlaff, S & Hornig, D (2010). Essential role of vitamin C and zinc in child immunity and health. J Int Med Res. 38(2), 386-414.
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.
o Feiz, HR & Mobarhan, S (2002). Does vitamin C intake slow the progression of gastric cancer in Helicobacter pylori-infected populations? Nutr Rev. 60(1), 34-6.
Background: Low vitamin C status may increase the risk of mortality from cancer and cardiovascular disease……. Conclusions: These data suggest that men with low serum ascorbate concentrations may have an increased risk of mortality, probably because of an increased risk of dying from cancer.
o Loria, CM, Klag, MJ, Caulfield, LE & Whelton, PK (2000). Vitamin C status and mortality in US adults. Am J Clin Nutr. 72(1), 139-145.
Approximately 90 epidemiologic studies have examined the role of vitamin C or vitamin-C-rich foods in cancer prevention, and the vast majority has found statistically significant protective effects. Evidence is strong for cancers of the esophagus, oral cavity, stomach, and pancreas. There is also substantial evidence of a protective effect in cancers of the cervix, rectum, and breast. Even in lung cancer, for which carotenoids show a consistent protective effect, there is recent evidence of a role for vitamin C. Vitamin C is an important antioxidant and free radical scavenger in plasma and acts to regenerate active vitamin E in lipid membranes. Although several different factors in fruits and vegetables probably act jointly, the epidemiologic and biochemical evidence indicate an important role for vitamin C.
o Block, G (1991). Epidemiologic evidence regarding vitamin C and cancer. Am J Clin Nutr. 54, 1310S-14S.
For cancers of the esophagus, larynx, oral cavity, and pancreas, evidence for a protective effect of vitamin C or some component in fruit is strong and consistent. For cancers of the stomach, rectum, breast, and cervix there is also strong evidence. Several recent lung cancer studies found significant protective effects of vitamin C or of foods that are better sources of vitamin C than of beta-carotene. It is likely that ascorbic acid, carotenoids, and other factors in fruits and vegetables act jointly.
o Block, G (1991). Vitamin C and cancer prevention: the epidemiologic evidence. Am J Clin Nutr. 53, 270S-282S.
Vitamin C is an essential nutrient whose protective role in carcinogenesis has been discussed for more than 50 years. Epidemiologic studies suggest that the consumption of vitamin C-rich foods is associated with a lower risk of cancers of the esophagus and stomach……. ascorbic acid can interfere with the metabolism of tumor promoters. It has also been postulated that ascorbic acid helps to prevent cancer by enhancing cellular immunity. In general, evidence suggests that vitamin C can inhibit the formation of some carcinogens.
o Glatthar, BE, Hornig, DH & Moser, U (1986). The role of ascorbic acid in carcinogenesis. Adv Exp Med Biol. 206, 357-77
1990: National Cancer Institute 130 scientist symposium on Vitamin C: ?Significant evidence of a reduced risk for cancers in persons with a higher intake of Vit C
o Block, American Journal of Clinical Nutrition (1991) 53:270s-282s.
Mega-dose Vit C can extend cancer patients life by as much as 6x.
o Murata, Medical tribune, July 22, 1981, and Hoffer, Pauling, J. Orthomolecular Medicine, Vol 5:3, 1990.
Vitamin C may block growth of tumors by destabilizing their ability to grow under oxygen-starved conditions.
o Goa, Ping et al (2007). HIF-Dependent Antitumorigenic Effect of Antioxidants In Vivo. Cancer Cell.12(3),230-8
Dietary Vit C reduces breast cancer risk (meta-analysis).
o Gandini, Eur J Cancer (2000);36:636-46.
Vit C reduces cancer risk and is especially effective in preventing lung, stomach, esophageal, breast, cervical, pancreatic and colon cancer.
o Am J Clin Nutr, 1992; Age Aging, 1993.
Lung cancer patients provided Vit C prior to, during and after radiation & chemotherapy had enhanced tumour destruction & significantly longer life-span.
o Jaakkola, Anticancer Research,(1992) 12, 599.
Increased intake of vitamin C from the diet, but not supplements, may slash the risk of mouth cancer by 48 per cent.
o Maserejian, NN, Giovannucci, E, Rosner, B, & Joshipura, K Prospective study of vitamins C, E, and A and carotenoids and risk of oral premalignant lesions in men. International Journal of Cancer, 120(5), 970-7.
A large 23 centre European study concludes that Vit C protects against cancers of the stomach and lower esophagus. At least 16 previous studies have shown Vit C to reduce the risk of stomach cancer.
o Mazda et al, Carcinogenesis 2006 27(11):2250-2257.
Background: Several antioxidant nutrients have been reported to be inversely associated with asthma. A study was undertaken to assess the independent associations of these nutrients with asthma in adults……. Conclusions: Symptomatic asthma in adults is associated with a low dietary intake of fruit, the antioxidant nutrients vitamin C and manganese, and low plasma vitamin C levels. These findings suggest that diet may be a potentially modifiable risk factor for the development of asthma.
o Patel, BD, Welch, AA, Bingham, SA, Luben, RN, Day, NE, Khaw, K-T, Lomas, DA & Wareham, NJ (2006). Dietary antioxidants and asthma in adults. Thorax, 61(5), 388-93.
Background: It has been suggested that a high dietary intake and high circulating concentrations of vitamin C may protect against ischemic heart disease……….Conclusion: The findings suggest that vitamin C has anti-inflammatory effects and is associated with lower endothelial dysfunction in men with no history of cardiovascular disease or diabetes.
o Wannamethee, SG, Lowe, GDO, Rumley, A, Bruckdorfer, KR & Whincup, PH (2006). Associations of vitamin C status, fruit and vegetable intakes, and markers of inflammation and hemostasis. Am J Clin Nutr. 83(3), 567-74.
OBJECTIVES--To determine whether vitamin C status, as measured by dietary intake and plasma ascorbic acid concentration, is related to mortality from stroke and coronary heart disease in people aged 65 and over. ….. RESULTS--Mortality from stroke was highest in those with the lowest vitamin C status. ………The relation between vitamin C intake and stroke was independent of social class and other dietary variables. CONCLUSION--In elderly people vitamin C concentration, whether measured by dietary intake or plasma concentration of ascorbic acid, is strongly related to subsequent risk of death from stroke but not from coronary heart disease.
Gale, CR, Martyn, CN, Winter, PD & Cooper, C (1995). Vitamin C and risk of death from stroke and coronary heart disease in cohort of elderly people. BMJ. 310(6994), 1563–66.