Ask just about anyone to name one vitamin that is helpful for colds and Vitamin C is bound to be the one named. Dr. Linus Pauling is credited with sparking interest in Vitamin C, not only for immune function but beneficial effects on heart disease, diabetes, and cancer. He personally used high doses of Vitamin C and felt it greatly reduced the number of colds he experienced. His claims received much attention beginning in the 1970’s, so that numerous studies were conducted in the next 3 decades. Analysis of these studies by Dr. Harri Hemila found an overall benefit in regards to prevention and duration. Results were more favorable in groups of participants more prone to stress, whether through sports or jobs (e.g. soldiers).
These findings are well supported by work done by Dr. James Wilson, who has analyzed the role of Vitamin C in our stress response, including the proper production and use of cortisol, the stress hormone. Perhaps the need for Vitamin C to prevent colds is even greater now than in the previous decades, owing to the fact that our lifestyles as a whole have become much more stressful?
Would taking Vitamin C be helpful for you? To answer this you might look at benefit versus risk. What are the risks of vitamin C supplementation? It is a water-soluble vitamin and has shown remarkably low toxicity. Because it enhances iron absorption, it is possible that it could lead to high levels of iron, so intake of iron should be assessed before taking mega-doses on a consistent basis. The only other side effect which occurs regularly is diarrhea, which is actually used by many practitioners to serve as a guide to knowing what the correct dosage is for a patient. It is commonly recommended that patients take 500 mg every hour until their stools are loose and watery, at which point they should stop and maintain a dosage 500 mg less than that which induced the effect.
Because it is water soluble and readily excreted, taking Vitamin C in smaller quantities throughout the day, and/or using a supplement which is sustained-release will increase its effects.
On a final note, Vitamin C absorption and usage has been shown to be enhanced in the presence of bioflavonoids, a large group of antioxidants from fruits and vegetables. Using a Vitamin C supplement which contains a 2:1 ratio of Vitamin C: Bioflavonoids is the optimal form for immune and stress-response support. Since the basis for such a supplement is to mimic how Vitamin C is found in nature, it makes sense that incorporating plenty of raw vegetables and fruits which are high in Vitamin C would be the ideal form for overall health. Produce with highest amounts of Vitamin C include oranges, grapefruits, sweet red pepper, broccoli, potatoes, and strawberries. A daily diet including 2.5 cups of a variety of fruits and vegetables is estimated to contain roughly 200 mg of Vitamin C, which may be adequate for some, but may well create a need to supplement for individuals under various forms of stress.
Vitamin C may seem like an “old housewife” remedy, but its safety and usage are well documented and its availability is widespread and economical, making it a perfect tool in helping to fight the viruses to which we are continually exposed.
Linus Pauling Institute Newsletter, January 2006; Jane Higdon, Ph.D.Updated in November 2009 by: Victoria J. Drake, Ph.D.
Reviewed in November 2009 by: Balz Frei, Ph.D.
Director and Endowed Chair, Linus Pauling Institute
Distinguished Professor, Dept. of Biochemistry and Biophysics
Oregon State University; Copyright 2000-2010 Linus Pauling Institute