The following information is courtesy of Dr. Mark Hyman, family physician and best selling author. If you would like to sign up for Dr. Hyman’s email newsletter to get more useful health and wellness information like this, please go to and enter your name and email address.

It’s that time of year-the weather starts to drastically shift, kids are back to school sharing germs, and most of us are busier and a bit more stressed than we were during the summer months. It’s the perfect storm for an immune system meltdown.

As with any other part of our health, prevention can go a long way in supporting the immune system, even if everyone around you is getting sick. There are lots of ways you can take advantage of foods with the right vitamins and minerals, as well as those with medicinal compounds, to help the body stay strong and healthy.

There are many, many nutrients that impact the immune system, but I want to share with you three that I feel are less talked about but very important for staying well all year long:

  1. Zinc: This mineral is essential for a healthy immune system, as it supports immune-boosting gene expression and cellular activity, while also acting as an anti-inflammatory and antioxidant. Because of the role of zinc in immunity, it’s important to get it regularly through your diet and, if needed, supplements. Foods high in zinc include red meat like grass-fed beef or lamb, chickpeas, cashews, almonds, hemp seeds, pumpkin seeds, and eggs, among others. If you feel like you’re coming down with something, try to up your intake of these foods.
  2. Selenium: Another necessary mineral to fight seasonal sickness, selenium has antiviral and anticancer properties, and also helps to counteract the aging of the immune system that occurs as the rest of the body ages. Brazil nuts are one of the richest sources of selenium; just one or two a day can get you the amount you need. Salmon, beef, turkey, and eggs are other great options; and other plant-based sources include sunflower seeds, brown rice, mushrooms, and spinach.
  3. Vitamin A: Along with its metabolites, vitamin A has a powerful impact on the immune system. It plays a special role in maintaining strong mucosal barriers, for example, those of the eyes, respiratory, gastrointestinal, and genitourinary tracts, so that they can keep out infection. Vitamin A is also important for the proper functioning of many kinds of immune cells and is necessary for the generation of antibody responses to specific antigens. When it comes to getting vitamin A through food, there are different kinds of compounds to consider:You can get vitamin A from animal sources like meat, eggs, fish, and organs like liver that contain preformed vitamin A (retinol or retinyl ester).You can also get vitamin A from plant-based sources like vegetables, especially those that are deep green, yellow, or orange. Kale, spinach, carrots, and sweet potatoes are all tasty examples. These plant-based sources contain provitamin A carotenoids (including beta-carotene).The difference between preformed vitamin A and provitamin A carotenoids is that preformed vitamin A can be assimilated by your body and used as is. Provitamin A carotenoids, on the other hand, have to be converted to retinol in the body, a process that may not be very efficient in some people due to genetics, gut health, and other factors. Also, it’s worth noting that some carotenoids such as lutein and zeaxanthin can’t be converted to retinol.So, while carotenoids are an important part of a healthy diet thanks to their own benefits, like antioxidant activity, sources of preformed vitamin A are the most efficient type of this vitamin for your body to use.

As we get further into cold and flu season, I hope you’ll enjoy the delicious flavors and health-promoting properties of the foods that contain these valuable nutrients. Remember, food is medicine! And by taking action now to prevent illness you can stay well all year long.

Wishing you health and happiness,
Mark Hyman, MD