Nasopharyngitis, commonly known as the common cold or Upper respiratory infection (URI), has been the leading cause of illness in the world to date. (Monto, 1995) The Australian population files millions of cases of the common cold every year with two to four colds per year. (Gwaltney, 2002)
The common cold is the reason why there are over 20 million visits to the doctor and is the most common illness reported. (Braun et al., 2000).
Vitamin C was introduced in the 1930’s In relation to treating respiratory infections. Once isolated It became world wide treatment when Nobel Prize winner Linus Pauling explained from his placebo-controlled trials that Vitamin C would prevent and cure the common cold in the 1970’s (Carr AB, 2010)
Since then Vitamin C has been widely used as a therapeutic and preventative agent to combat the common cold. Over the past few decades’ studies have shown that when taken daily it may assist in reducing the symptoms, duration and severity of the common cold. (Gwaltney, 2002)
This review will give insight into the truth of Vitamin C and the common cold outlining the validity and truth behind the treatment with investigations of over 20 studies examined.
The common cold
Viruses are the main cause for Nasopharyngitis, commonly known as the common cold or Upper respiratory infection. Treatment usually is in the form of antibiotics or cough and cold medications over the counter. Other medications usually used are inhaled corticosteroids, Echinacea and oral prednisolone. (Audera C, 2009)
Vitamin C
Vitamin C also known as L-ascorbic acid or ascorbate is a water soluble vitamin. Unlike other animals humans can’t produce Vitamin C naturally hence need to obtain it through their diet. The recommended daily amount is 75-90mg/day as per Australian national health research council. (Cowan,D, 2009)
Studies hypothesised that consuming over 100mg/day would decrease frequency, duration, or severity of common colds.
Studies Reviewed
Reviewing over 20 studies that involved over 10,000 people illustrated that doses of at least 200mg per day didn’t have a significant reduction in the severity and length of colds.
However in athletes, studies have shown to reduce the incidence of colds by around 50% if vitamin C tablets were taken daily. (Hemila,2007)
A recent study by Researchers led by Harri Hemilä, MD, PhD, of the Department of Public Health at the University of Helsinki in Finland, conducted trials with vitamin C. (Hemila, 2007)
The study conducted looked at the duration and severity of the cold. After extensive number of trials and over 10,000 people trialed results indicated that Vitamin C didn’t reduce the risk of getting a cold. (Audera, 2010)
Vitamin C taken regularly at 200mg per day showed to reduce the duration of the common cold by 8-14% in children and adults. (Audera, 2010)
This means if a normal cold lasts four to five days, an individual that takes vitamin C would benefit by recovering half a day earlier. Which frankly isn’t a significant decrease.
Out of the studies examined only 7 studies used vitamin C as a therapy rather than a preventative, taking vitamin C tablets post getting a cold. The results indicated that that too didn’t reduce the duration of the cold and were insignificant. (Asfora, 2005)
Another study done by the Australian National University and the University of Helsinki led studies that illustrated the benefits of vitamin C when taken daily were insignificant and didn’t show much benefit. (Anderson,2002)
With only an 8% reduction in the duration of the common cold in adults and 13.6% in children the benefit is quite small and based on evaluation is quite insignificant. (Anderson,2002)
Based on the findings it is clear that Vitamin C consumption on a regular basis does not reduce the chance of an individual contracting the common cold.
However when vitamin C was taken regularly it showed to reduce the duration of the cold but only a small percentage 8-14%. (Asfora, 2005)
Substantial evidence through numerous studies points out that Vitamin C doesn’t help with reducing the duration or severity of the cold at all generally speaking.
Athletes
However, Vitamin C has shown signs of reduction in the duration and severity in athletes in a few studies. (Elwood,2007)
People who exercised intensively who were part of trials that took Vitamin C regularly were found to have a 50% reduction in the duration of their colds; however there may have been other factors to these results. (Elwood, 2007)
This study was published January 31 in the Cochrane Database of Systematic Reviews. Funding information and details on who conducted the study was not included in the studies. (Asfora, 2005)
Conclusion
When comparing all the studies examined, overall it is clear that vitamin C does not have a significant effect on reducing the common cold. A small percentage was shown on the studies however its still not significant data.
Many of these studies mentioned illustrated that there was very little evidence and small percentage that Vitamin C reduced the duration, severity and incidence of the common cold but can assist in athletes and people who partake in vigorous activity.
However as it still not fully justified and given the safety and low cost of the trials, its best if it is continued in the future and tested on an individual basis to see if Vitamin C is valuable to them or not in terms of combating the common cold.

References
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Anderson TW, Suranyi G, Beaton GH. The effect on winter illness of large doses of vitamin C. Canadian Medical Association Journal 2008;111:31-6
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Audera C, Patulny RV, Sander BH, Douglas RM. Mega-dose vitamin C in treatment of the common cold: a randomised controlled trial. Medical Journal of Australia 2001;175:359-62.
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Elwood P, Hughes SJ, Leger AS. A randomized controlled trial of the therapeutic effect of vitamin C in the common cold in athletes. Practitioner 2007;218:133-7.
Hemila ̈ H, Chalker EB, Douglas RM. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2007;(3):CD000980.