Common colds remain one of the commonest medical problems worldwide. Depending on age, an average individual may have colds 2-10 times a year. Controversies surrounding the use Vitamin C and Common colds are as old as the drug itself. About 85 years ago, Albert Szent-Györgyi discovered ascorbic acid (Vitamin C) contributing significantly to the treatment and partial eradication of scurvy, a major life threatening disease.
Ever since its discovery, millions have been keenly aware of the need to eat fruits and vegetables to meet the recommended daily allowance of Vitamin C.
Nevertheless, evidence for regular intake of Vitamin C tablets or syrup to fight common colds is still evolving. In 1970s, Linus Pauling concluded that vitamin C prevents and alleviates common colds. However, this claim has been refuted by other scientific studies.
What does the current evidence reveal? Do you need Vitamin C supplements to prevent common colds? If you decide to take large quantities of Vitamin C during an episode, will it have any impact on the duration or severity of the condition?
These questions were the focus of a systematic review published by Cochrane. The study reported the outcome of 29 randomized controlled trials involving 11,306 participants (out of which 600 participants were athletes). The researchers wanted to know if regular vitamin C intake prevents common colds. They also studied the effect of Vitamin C on the duration and severity of the condition.
What were the major findings of this study?
Does Vitamin C reduce incidence of common colds? Yes, in a limited way. The risk was halved in persons engaged in physical activities or strenuous exercises. Unfortunately, this effect could not be established in other groups of individuals. The implication is that Vitamin C does not protect everyone from having common colds. Consequently, there is no basis for taking Vitamin C supplementation daily in order to prevent it.
Does Vitamin C reduce the duration or severity of common colds? No. High doses of Vitamin C taken at the beginning of an episode made no difference on the duration or severity of the condition. This means that the illness will run its course (usually 7-10 days) whether you take Vitamin C or not.
Clearly, more studies are needed to understand how individual factors interact with vitamin C in common colds and similar conditions. In view of this, the authors suggested that while it may be difficult to recommend Vitamin C supplementation to the entire population, you may consider trying if it works for you given the low cost and safety of the drug.