Vitamin C for a very long time had been associated with being effective against common cold. A new research that had come out in the journal PLoS Medicine reports that such claims may not be justified.
Researchers for the study had looked into the studies made asserting the claims of the researchers on the association between vitamin C and common colds done in past 65 years. All the studies have compared 200mg of vitamin C tablets with a placebo.
Of the 23 studies the researchers have found dealing with the preventive effect of vitamin C on common colds, there were no significant associations between the intake of supplementary vitamin C and reduced risk of common colds.
However the scientists did find association between intake of supplementary vitamin C and prevention of common cold in people exposed to harsh physical exertions and extreme weathers.
The researchers had also looked into the effect of vitamin C on shortening the duration of common cold, and found no evidence to establish the theory. However, in one study where the people have taken a very high dose of 800mg of vitamin C supplements daily, found their cold duration to be shortened by about 50% when compared with people who took the placebo.
Reference: PloS medicine, June 2005