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4 Tips To Boost Your Immune System During Cold & Flu Season

Sleep, exercise, vitamin D, and the flu shot can all help boost your immune system.

Cold and flu season is now upon us. That compounded with the ongoing coronavirus pandemic means it’s time to focus on our immune systems.  

Immune systems are pretty effective against many germs and viruses, but it takes time to fight them. And this year has added stress for many due to the many impacts of the coronavirus pandemic. "So, anything you can do to mitigate that stress by simple measures is going to be very helpful," says Josh Knox, a physician assistant by training and a clinical associate professor at Marquette University’s physician assistant program.

Knox shares some tips to help strengthen your immune system this cold and flu season:


Our bodies need sleep for our immune systems to work properly. "At night, besides your tired aching bones and muscles, your immune system is rebuilding while you’re sleeping," Knox explains.

Our bodies also produce and release signaling proteins called cytokines that orchestrate our immune system while we sleep. T-cells are also produced at night, and Kox says "there's also some evidence that those T-cells stick to their targets a little better when we get adequate sleep."

The National Sleep Foundation recommends that adults sleep seven to nine hours a night to stay healthy. While not enough research has been conducted related to COVID-19, other researchhas shown that people sleeping six hours or less were more than four times more likely to catch other cold viruses. 


People getting the recommended 150-300 minutes of moderate or vigorous aerobic exercise and two weight-like training sessions during the week helps antibody formations. Exercise also helps the body's B-cells that make antibodies, according to Knox.  

"Normally, our white blood cells or those T-cells are kind of hanging out on the edge of our blood system, and exercise actually shocks them into activity and it turns them over more efficiently," he explains.

Studies have also shown that people who exercise regularly are less susceptible to cold and flu-like viruses, and have reduced upper respiratory infections with shorter periods of being sick. "There is one study that shows that those individuals who are regularly exercising potentially can prevent or at least reduce the severity of severe reactions to COVID-19," says Knox. 

Vitamin D

While there are plenty of vitamins to choose from over the counter, "there's probably only one supplement that has enough data to say something intelligent about it at this time — and that is vitamin D," says Knox.

Vitamin D helps regulate calcium and phosphate to keep bones, teeth and muscles healthy. Knox notes that the best way to get it is through sunshine and healthy meals, but taking supplements can help your immune function as well. 

"There is reams of data from other viruses and other upper respiratory infections that suggest that individuals are less susceptible to cold viruses and upper respiratory viruses when they have adequate vitamin D," says Knox.

When it comes to the coronavirus, a study has shown that people will have a less severe case and have a lower risk of death when they have enough vitamin D, according to Knox. 

Get the flu shot

In addition to getting good sleep, exercising, and getting enough vitamin D, Knox says that getting the flu shot this year "is more important than ever."

He notes that people could be weakened by getting the flu and become more susceptible to COVID-19 or need to be hospitalized with the flu and risk further exposure to the coronavirus.  

"The flu vaccine does not cause the flu," states Knox. "Very few people have adverse reactions to it, beyond very mild ones, and I think it's essential for everybody to get it this year."

Audrey Nowakowski is a WUWM host and producer for Lake Effect.