Can Vitamin C Intake Boost Immunity? Can Vitamin C Intake Boost Immunity?

Is Vitamin C beneficial for immunity?

With winter slowly kicking in, it is good to ensure a powerful nutritional arsenal to fight common cold.


Common cold is a viral infection of the upper respiratory tract, the nose and the throat. Although usually not a serious condition, it is a very unpleasant one accompanied by symptoms such as runny nose, sore throat, cough, watery eyes, sneezing and congestion. Children are more susceptible to colds, but even healthy adults may experience colds on average five times a year.1


Traditionally, it has been thought that loading on Vitamin C is the best way to fight a cold. It is the most popular selling Vitamin in the world with sales exceeding $7.5 billion per year.2


The popularity of this Vitamin as a “panacea” is attributed to a very influential American scientist and Nobel-laureate, Linus Pauling, that suggested that Vitamin C could prevent and alleviate colds and other diseases.3


Although some of the claimed benefits hold true, they were definitely overstated and they were not tested in a diverse, representative of the population, sample. Currently, the current scientific literature remains inconclusive as to what the effect of Vitamin C intake is on common cold is.


A large-scale Cochrane meta-analysis (review of several published studies) published in 2013 suggested that regular vitamin C supplementation seems to have a consistent effect in reducing the duration and severity of common cold symptoms, but the therapeutic studies did not show such an effect.4 Also, although Vitamin C may affect the duration of the cold, it has no impact on the incidence rate. Even megadoses of this Vitamin seem to not alter the results, but instead cause nausea, diarrhoea and stomach cramps.


Is there anything else we should be taking for common cold?


Zinc supplementation seems to be helping with reducing the duration of common cold.5


Zinc is an important cofactor of many enzymes in the human body, including ones of the immune system. A 2012 systematic review and meta-analysis of randomised-control-trials showed that oral zinc formulations may shorten the duration of symptoms of the common cold.6


Several other remedies such as Ginseng, Garlic, Vitamin D and Echinachea have been studied with no real evidence of benefit. Also, vapour rub containing camphor, menthol and eucalyptus oil, applied to the neck and chest had virtually no benefit and could lead to a rash or a burning sensation.


What is certain is that hand-washing and maintaining a hygienic environment helps with preventing the spread of common cold. It’s commonly believed that a sneeze propels mucus from your body at 100 mph, landing it 30 feet away.


The “Mythbusters” set out to test this myth and busted it. But what they did find was still impressive! Adam sneezed at 35 mph landing it 17 feet away, compared to Jamie who sneezed at 39 mph and reached 13 feet! That’s definitely still enough to spread thousands of germs through the air, so make sure you cover that sneeze, especially if you’ve got a cold, the flu, or COVID-19.


Remember to practice good hygiene and wash your hands regularly. And you may want to save your money from overdosing on Vitamin C supplements. Instead you try some Zinc.


Stay healthy!


The Nutrigenius team




1.  Worrall G. Common cold. Can Fam Physician. 2011;57(11):1289‐1290.


3.  Hemilä H. Vitamin C supplementation and the common cold–was Linus Pauling right or wrong?. Int J Vitam Nutr Res. 1997;67(5):329‐335.

4.  Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;(1):CD000980. Published 2013 Jan 31. doi:10.1002/14651858.CD000980.pub4

5.  Wang MX, Win SS, Pang J. Zinc Supplementation Reduces Common Cold Duration among Healthy Adults: A Systematic Review of Randomized Controlled Trials with Micronutrients Supplementation [published online ahead of print, 2020 Apr 27]. Am J Trop Med Hyg.

6.  Science M, Johnstone J, Roth DE, Guyatt G, Loeb M. Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials. CMAJ. 2012;184(10):E551‐E561. doi:10.1503/cmaj.111990