Vitamin C and the Common Cold
Many people believe that taking large doses of vitamin C will reduce their cold symptoms -- or even prevent colds altogether. However, research studies have shown that there is no connection between the common cold and vitamin C. In fact, taking large doses of vitamin C may cause harmful side effects.
The connection between vitamin C and the common cold has been a source of controversy for decades. Many people are convinced that taking large quantities of vitamin C will prevent colds or relieve cold symptoms. To test this common cold myth, several large-scale, controlled research studies involving children and adults were conducted.
To date, no conclusive data have shown that large doses of vitamin C prevent colds.
For people who take vitamin C every day, it may reduce the severity or duration of cold symptoms, but there is no clear evidence supporting this. Once symptoms of the common cold begin, taking vitamin C has not shown any benefit in reducing the severity or duration of cold symptoms.
Taking vitamin C for cold prevention could provide some benefit for people exposed to brief episodes of intense exercise or extreme cold-weather environments.
Taking vitamin C over long periods of time in large amounts may be harmful. Too much vitamin C can cause severe diarrhea, a particular danger for elderly people and small children.