Most people believe that consumption of Vitamin C will prevent and cure common cold but this is not entirely true. Although Vitamin C plays a vital role in our immune system, it shows to be not as effective as we think, to support our beliefs (according to the studies, anyway).

In the 1970s, Linus Pauling, a renowned American chemist suggested that consumption of Vitamin C could successfully treat/prevent the common cold. However, due to lack of consistent studies with positive findings since, this has resulted in further confusion & controversy. 

A very well known 2007 Cochrane Systematic Review carried out placebo-controlled trials involving the use of at least 200 mg/day vitamin C taken either continuously as a prophylactic (for prevention) treatment or after the onset of cold symptoms. Consumption of vitamin C ‘continuously’ as a prophylactic treatment resulted in reduction of cold duration by only 8% (1 day) in adults and 14% in children. At the same time, trials involving athletes and individuals exposed to extreme physical activities and weather conditions, consumption of ‘250m-1g /a day’ reduced cold incidence by 50%. Furthermore, Prophylactic use of vitamin C did not significantly reduce the risk of developing a cold in the general population. 

In conclusion, consumption of Vitamin C might not be able to reduce the incidence of a common cold but sufficient consumption of 250mg+ a day may certainly reduce the cold duration by as long as one day, which can be appreciated by many busy and working individuals. Athletes and other individuals exposed to strenuous physical activities and weather conditions may also greatly benefit from consuming sufficient amounts of vitamin C.