Are you getting the nutrients you need to stay healthy and keep your immune system functioning optimally? Frequently, health care professionals dismiss the need for supplemental vitamins or minerals. They suggest that you can get all the nutrition you need from a well-balanced diet.

The trouble is that too many Americans are not getting the nutrients they require for a healthy immune system. That is the conclusion from a study of 26,282 adults between 2005-2016 (Nutrients, June 10, 2020). The investigators found that a surprisingly large proportion of us are not getting what we need in our diets. For example, 84% did not get adequate vitamin E, while 95% did not have enough vitamin D in their food. These vitamins are critical for immune system function.

Vitamins A and C are also essential for healthy immune cells, and nearly half of the study participants were getting too little of each of those. Most people take these vitamins for granted and assume they are getting plenty from their diet.

Where would you get these vitamins? The best source for vitamin A is probably liver, but a lot of people don’t like it. Even people who don’t mind it rarely eat it. That leaves carotenoid-rich green, yellow and orange vegetables: broccoli, kale, spinach, carrots, squash and sweet potatoes, among others. Fruits like apricots, cantaloupe, mangos or peaches can also supply vitamin A-forming carotenoids.

Some fortified dairy products provide vitamin A, and so do fish like salmon or tuna. Fatty fish like this can also provide vitamin D. Dairy products are also fortified with this sunshine vitamin. Otherwise, the best source of vitamin D is cod liver oil — not a highly popular choice for most folks!

We were surprised to discover that so many Americans are low in vitamin C. A lot of people believe that a few ounces of orange juice in the morning will cover their needs. Yet the latest survey found 46% of us are not getting enough. Besides citrus fruits, red peppers, kiwifruit, strawberries and tomatoes are good sources.

In addition, about 15% of Americans were not eating enough foods that supply zinc, a mineral that the body must have to mount a robust immune response. Where would you get this nutrient? Oysters are very rich in zinc, but, like liver, they don’t often show up on family dinner tables. Seafood, beef and pork are also decent sources, and vegetarians can get zinc from beans, almonds, cashews, chickpeas or pumpkin seeds.

Most people have no idea that one of the medications they take may be depleting their bodies of zinc. Blood pressure pills such as lisinopril or valsartan may be culprits, along with diuretics like hydrochlorothiazide.

With COVID-19 on the rampage, we all need our immune systems functioning as well as possible. A well-balanced diet with lots of fruits, vegetables, nuts, seeds, legumes and whole grains is a great place to start. You might also want to consider a supplement as dietary insurance.

You can learn more about your specific nutritional needs and medicines that may interfere with vitamins and minerals from Dr. Tieraona Low Dog’s book, “Fortify Your Life.” If you can’t get it from your local library, you can buy a paperback copy from the Books section at

Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio. In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email them via their website:

—King Features

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