Can vitamins prevent a cold?

Photo courtesy Tina Franklin

Immune system functioning is top of mind for many of us these days as COVID has really brought attention to how our bodies fight off infection. Eating well can definitely play a role in how we respond to infectious agents, such as viruses. Being deficient in certain nutrients, like vitamins C and D and zinc, can certainly play a role in how our immune systems work and make us more susceptible to various viruses and bacteria.

While we are seeing many supplement companies promoting their products as supporting a healthy immune system, there’s one company that, I feel, is taking advantage of the regulations to make claims.

Check out this TV commercial which states that this product can prevent colds. While if you simply watch and listen to it, you might believe that for the average person, it can help to prevent colds.

Take a look and see if you agree with me.

Did you happen to notice the small print near the bottom of the screen? It states

“Emergen-C Immune+ may help prevent colds in those undergoing physical stress”.

Now before I go any further, I want to point out that there’s a difference between preventing colds in the first place and actually impacting the duration and severity of a cold. But more on that later.

Vitamin C was long touted as a supplement to take which could help prevent your catching a cold. While it was a controversial topic for a while, the scientific research simply didn’t back it up – that is, for the average person.

Yet many still believe in the prevention theory. It’s something I hear, all too often, as a dietitian.

Commercials like the one above don’t help.

The latest research on the topic looked at 29 trials and more than 11,000 participants and found that, in the general population, the trials involving most subjects – almost 11,000- regular consumption of vitamin C did not prevent the development of common cold.

But here’s the catch. The research shows, that in people who had been exposed with physical and environmental stresses such as marathon runners and soldiers that consumed vitamin C, their incidence of getting a cold was reduced by half. But take note, the article points to the soldiers being on subarctic exercises.

Hence the small print in the commercial.

I’m not sure that the woman, in the commercial, doing leg work on a mat would qualify.

What this commercial shows me is how supplement makers can get around the regulations.

When I asked Health Canada how this is allowed, Tammy Jarbeau, Senior Media Relations Advisor of the Communications and Public Affairs Branch Serving Health Canada and the Public Health Agency of Canada stated,

“Clinical studies demonstrated a significant effect of vitamin C supplementation on the incidence of colds in individuals under physical stress. The term ‘physical stress’ is used for ‘heavy physical exercise’ in the published literature.”

Do you think that the commercial is aimed at marathon runners or soldiers in extreme cold or is it aimed at the average person watching TV?

Do you think the commercial is misleading?

Now to various nutrients and their impact on the severity and duration of colds. There is indeed plenty of research which shows that taking certain supplements, such as vitamin C and zinc, can shorten the how long your cold lasts and just how awful you feel when you have a cold.

So if you have been taking these supplements in the hope that they can prevent your catching a cold, consider putting them away in your medicine cabinet and pulling them out when you actually catch one.