Vitamin C in the Prevention and Treatment of the Common Cold.

During the winter months, absenteeism or decreased productivity at work or school can often be attributed to symptoms of the common cold. Many people seek over-the-counter (OTC) products for their symptoms, and some of the commonly purchased products are those with high-dose supplements of vitamin C (ascorbic acid). The common cold causes enormous morbidity worldwide, and it is important to know the effects of vitamin C for both preventive and therapeutic purposes to correctly recommend the proper OTC product for these symptoms. The purpose of this article is to review the current data on the relationship between vitamin C and immune function, specifically, the utility of vitamin C supplementation in the prevention and treatment of the common cold.