The winter months often are often associated as the time of year when we are more susceptible to coughs and colds. The common cold is one of the most widespread illnesses and is a leading cause of visits to the doctor and absenteeism from school and work. Although there has never been a definitive explanation why we might be more at risk during the colder months, there are some evidence-based recommendations as to how we can reduce either the number of colds we encounter or how long they last. Here, we’ll take a look at some of the fact and fiction of some of the most popular supplements for the cold season.


Inside our body are trillions of bacteria that can have an impact on our immune system. Probiotics are bacteria that, when taken in adequate amounts, offer health benefits to the body. Studies have shown that probiotics have the ability to help stimulate our immune function and so could possibly help reduce the risk of getting a cold. However, different products use different types of bacteria and use different doses so if you are considering taking probiotic supplements then it is important to find one that has been shown to be effective in scientific studies. For example, when children took ProVen Fit For School daily for a period of six months, absenteeism was reduced by 30% compared to a placebo group1.

Vitamin C

One of the most popular and well-known supplements for colds, vitamin C is known as an essential vitamin because humans cannot produce it in the body nor can we store it. We have to a make sure that we get enough through our diets. In health populations, vitamin C has not been rigorously shown to reduce our chances of catching a cold but has been shown to reduce the duration of colds1. Plus, in athletes, who are at an increased risk of illness, vitamin C has been shown to reduce the risk of catching a cold by about a half2. Research has used anywhere between 200-2000mg of vitamin C in studies.




Echinacea, like vitamin C, has become one of the most popular supplements to help ward off winter coughs and colds. Echinacea is a herb that has been used for centuries to help support our bodies natural defences. Although some studies have shown Echinacea to have no effect, there are many more studies that have shown that it can reduce both the number and duration of colds, although not on the severity of symptoms3. Echinacea has been shown to reduce the risk of catching a cold when taken every day and has also been found to help reduce the duration of illness when it is taken at the first sign of a cold.


Although there has not been much research into the optimal dose, studies have used anywhere from 200-1500mg a day, but these higher doses have often not been shown to be any more beneficial. After processing, echinacea bioactives can be sensitive to light and heat so it may be best to store echinacea in a cool (5°C or lower) and dark place.


Zinc is an essential mineral involved in regulating many enzymes. It is an antioxidant and immune-boosting supplement that is most commonly supplemented to reduce the frequency of illness. Although zinc deficiencies can be rare, zinc is lost through sweat, making supplementation important for athletes that don’t get a lot of zinc through food. A review in 2012 found that zinc administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people. When supplemented for at least five months, it reduces cold incidence, school absenteeism and prescription of antibiotics in children4.

Supplemental doses range from 5-45mg, although the upper limit is often for those who have a large deficiency.


Our mothers and grandmothers often had a warming hot blackcurrant, lemon and honey drink at hand when we were ill. This anti-oxidant drink harks back to those times but adds in some additional ingredients like vitamin C, elderberry, bee propolis, beta glucans and zinc, specifically to help maintain the body’s defences and in doses that have been shown to be effective at reducing either the severity or duration of colds.


While the cure for the common cold has eluded scientist for centuries, we do have a better understanding of what works and what doesn’t work when it comes to helping relieve the symptoms. As a word of warning, more is not always better when it comes to supplement doses so be careful to read the packaging. This goes for pregnant women as well who should note that many supplements have not been specifically studied during pregnancy – again, be sure to read the label.


Finally, it is not just about supplements and herbal remedies. Remember to take a common sense approach and think about these other steps, which have been shown to reduce the risk of getting the flu:


  • Wash your hands. Use disinfectant wipes on telephone and computer keyboards to prevent the transfer of viruses.
  • Avoid close contact with sick people. And stay home if you have a cough and fever. Cover coughs and sneezes with tissues or the crook of your arm.
  • Get plenty of sleep. Sleep-deprived volunteers in one study mustered half the immune response to a flu shot compared with those getting normal sleep.
  • Eating well, exercising regularly, and reducing stress may also bolster immunity.
  • If you smoke, quit. Smokers are vulnerable to the flu and its complications.



1)    Garaiova, I., Muchová, J., Nagyová, Z., Wang, D., Li, J. V., Országhová, Z., ... & Ďuračková, Z. (2014). Probiotics and vitamin C for the prevention of respiratory tract infections in children attending preschool: a randomised controlled pilot study. European journal of clinical nutrition.

2)    Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. The Cochrane Library.

3)    Shah, S. A., Sander, S., White, C. M., Rinaldi, M., & Coleman, C. I. (2007). Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. The Lancet infectious diseases7(7), 473-480.

4)    Singh, M., & Das, R. R. (2012). Cochrane Review: Zinc for the common cold. EvidenceBased Child Health: A Cochrane Review Journal7(4), 1235-1308.