It has been claimed that very large daily doses of vitamin C (³1 g per day) prevent, or are effective in treating common colds and other infections, psychiatric conditions, hyper-cholesterolaemia and atherosclerosis, cancer, and other diseases, while enhancing immunological responsiveness, wound healing, and physical performance (Irwin & Hutchins, 1976; Olson & Hodges, 1987). Large doses have also been said to lower blood cholesterol, facilitate iron absorption, and promote the mobilization and elimination of heavy metals such as lead, mercury, cadmium and copper. Linus Pauling recommended daily intakes of 2400 mg, which is equivalent to the amount rats produce calculated on the basis of body weight per day. However, such claims have not been supported by research. Although many controlled clinical studies have been conducted to test the protective effect against colds of gram-doses of vitamin C, most indicate only a small positive impact in terms of reducing the incidence, shortening the duration, and alleviating the symptoms of the common cold. It has been suggested that some of these benefits may be due to a placebo effect (Combs, 1992).