Vitamin C & Disease Treatment - Part2

Diabetes mellitus

Numerous observational studies have found that people with diabetes have lower plasma levels of vitamin C (approximately 30% lower) than do people without diabetes. However, a number of methodological flaws have been attributed to such studies, and it is not clear whether diabetes is the cause of lower plasma levels of vitamin C. Recently a large population-based study found no difference in blood levels of vitamin C between over 200 individuals with newly diagnosed diabetes and 1,800 individuals without diabetes once dietary intake of vitamin C and cigarette smoking were taken into consideration . Though few studies have demonstrated improved blood glucose levels upon supplementation of diabetic individuals with vitamin C, doses of between 100 and 600 mg of vitamin C daily have been found to normalize cellular sorbitol levels, which may have implications for decreasing some of the long-term complications of diabetes. Cardiovascular diseases are the leading cause of death in individuals with diabetes (See Disease Prevention: Cardiovascular Diseases). Vitamin C has also been found to improve blood vessel dilation, which is often impaired in diabetic individuals (See Disease Treatment: Cardiovascular Diseases). The link between cardiovascular diseases and diabetes may be related to increased oxidative stress, giving credibility to the idea that the antioxidant properties of vitamin C may benefit individuals with diabetes. While the role of vitamin C in the management of diabetes is by no means clear, maintaining an adequate intake of vitamin C may help prevent some of the complications of diabetes.

Common cold

The work of Linus Pauling stimulated public interest in the use of large doses (greater than 1 gram/day) of vitamin C to prevent infection with the viruses responsible for the common cold. Reviews of the research conducted on this issue over the past 20 years conclude that, in general, large doses of vitamin C do not have a significant effect on the incidence of the common cold. However, a few studies have indicated that certain susceptible groups (e.g., individuals with low dietary intake and marathoners) may be less susceptible to the common cold when taking supplemental vitamin C. Additionally, large doses of vitamin C have been found to decrease the duration and severity of colds, an effect that may be related to the antihistamine effects found to occur with large doses (2 grams) of vitamin C.