The concept of our immune system is so abstract; we can’t see it, touch it or hear it. It’s hard for us to visualize it, yet we’re constantly in search of the best ways to support, fortify and boost it. Whether it’s the common cold, the flu or COVID-19, these seven key strategies will help you boost your immune system and protect your wellness year-round.

Get ample sleep. Sleep is essential for optimal immune function. Sleep deprivation, simply put, leaves us vulnerable. Our odds of getting sick are as much as four times higher when we get less than six hours of sleep a night.

Keep in mind that gut health is everything. Our gut is filled with a vast community of microorganisms that directly influence our immune system. Factors that negatively affect our gut bacteria include antibiotics, alcohol and a sedentary lifestyle. Factors that positively benefit our gut bacteria include a diet of fiber-rich vegetables and fruits, regular exercise and probiotics.

Include probiotics in your diet. Probiotics are linked to a full spectrum of health benefits, particularly gut support, which plays a key role in a healthy immune system. Top sources of probiotics include yogurt, kefir and kombucha. If you opt for probiotic supplements, look for live active cultures that are refrigerated, versus products that have potentially been sitting on shelves for months.

Consider taking a vitamin D supplement. Maintaining optimal blood levels of vitamin D appears to help maintain our body’s defense against infection. Several studies have also shown that people with low levels of vitamin D are more likely to test positive for COVID-19 than those with normal levels. We make vitamin D with the help of sunlight, but it’s challenging to get enough through our diet. I typically recommend supplementing with 5000 IU vitamin D, especially for those who aren’t getting at least 15 minutes of direct sunlight regularly.

Add zinc to your daily regimen. Zinc, especially in the form of lozenges, may prevent viruses from multiplying or attaching to our throat and nose. A handful of trials have shown that taking 75 milligrams of zinc daily translated to one to three days of fewer symptoms for colds. That said, it also seems that while zinc may be an effective prevention or treatment strategy for some, it has little to no effect in others.

Get your vitamin C! Vitamin C doesn’t necessarily prevent us from catching a cold, but it may help shorten the duration by a few days. In ultra-endurance athletes, however, supplementing with vitamin C has been shown to significantly reduce the risk by as much as 50 percent. There are no completed controlled trials of vitamin C in patients with COVID-19, though more than 30 studies are underway and reports are promising, with few safety concerns. I typically recommend 1,000 mg vitamin C in divided doses.

Finally, don’t forget the obvious. It goes without saying but follow the guidelines we’ve been hearing from health experts for almost an entire year now. Mask up. Wash your hands like it’s your job. Use sanitizer when you are unable to wash your hands. Maintain social distancing. And if you do get sick or have any symptoms of COVID-19, do your part and stay home.