Immunity is on a lot of people's minds right now as the campaign to vaccinate the public against COVID-19 gets underway and another flu season kicks into high gear. We know that a healthy immune system gives the body the protection it needs to ward off illness or prevent an existing illness from becoming worse than it already is, so we want to make sure we’re giving our immune system all that it needs to put up a good fight.
Naturally, many companies looking to take advantage of this current focus on immunity are flooding the market with supplements or “super foods” that they claim will “boost” or “support” the immune system. While getting proper nutrition is a key component of immunity, it’s important to understand that no single nutrient, food, supplement, or vitamin will boost your immunity in and of itself. Rather, a healthy immune system depends on several vitamins and nutrients working in concert. As part of a healthy eating plan, try to get all the following nutrients—ideally from foods that contain them—on a daily basis:
- Beta carotene—found in oranges, carrots, sweet potatoes, and mango.
- Vitamin C—found in citrus fruits like oranges, grapefruits, lemons, and limes, as well as in berries, melons, and even tomatoes and bell peppers. It only takes about 6 ounces of orange juice to meet your daily requirement. There’s no need to exceed 500 mg per day, as doing so may cause gastrointestinal distress and it will just be passed through your system.
- Zinc—can be found in wheat germ and beans, nuts, and tofu but tends to be absorbed better from animal sources like beef and seafood. If you’re buying zinc, choose zinc sulfate and take 220 mg once a day only for 10 days. More is not better with zinc.
- Vitamin D—found in fatty fish, like salmon and tuna, and in eggs. Milk and some juices are fortified with it. If buying it, choose vitamin D3 and take 1000-3000 IU per day. Again, more is not better.
- Probiotics—lots of studies show that the immune system starts in the gut. The good bacteria promote gut health. Found in cultured yogurts and fermented foods like kimchi. If buying, choose Culturelle® and take 1-2 tablets per day. More is not necessary.
- Protein—comes from both animal- and plant-based sources like milk, yogurt, eggs, beef, seafood, chicken, lentils, and beans. Aim for 50-125 gm per day, depending on your weight (1.0-1.2 gm of protein per kg of body weight).
However, keep in mind that proper nutrition is just one key component of healthy immunity. In addition to getting all the nutrients listed above, be sure to drink water, water, and more water! Aim for 64 ounces of good-old plain water a day. Also, be sure to maintain other healthy lifestyle habits that help promote strong immunity, such as getting adequate sleep and exercising regularly.
A few more reminders that will help you stick with a healthy eating plan: Before you head out to the grocery store, make a shopping list. To make the most of your food-buying dollar, look for specials and sales and use leftovers for soups and stews. Preplan the nights that you’re going to cook and nights to bring in carry out.
I hope all these suggestions will help keep you as healthy as you can be as well as demystify some of the things you might have heard about nutrition. When it comes to healthy eating, knowledge truly is power.
Laurie Syring, RD/LD, is Clinical Nutrition Manager at ProMedica Flower Hospital.