You’re washing your hands often, practicing social distancing and perhaps wearing a mask to lessen your risk of spreading or contracting COVID-19. There is one more thing you can do to reduce your risk of getting the virus: eat a healthy diet. A team of researchers is calling for public health officials to add nutritional guidance regarding the foods that can help keep you healthy to messages about ways to protect yourself from COVID-19.

Good nutrition is often given lip service when talking about ways to boost the immune system, but it's more important than many realize. Researchers from Oregon State University’s Linus Pauling Institute, the University of Southampton in the United Kingdom, the University of Otago in New Zealand and the University Medical Center in the Netherlands argue that multivitamin, mineral and fatty acid supplements are a safe, effective and inexpensive way to help our immune systems fight off COVID-19 as well as other acute respiratory tract diseases. They also urge that supplementing vitamins C and D, even in amounts that exceed current guidelines, can also make you better able to resist viral infections.

Vitamin C promotes the body’s production of many types of immune cells. It also helps maintain the structure and function of these cells.

Nutrition plays a major role in supporting your immune system, and more needs to be done to get this information to people seeking protection from the novel coronavirus.

“The present situation with COVID-19 and the number of people dying from other respiratory infections make it clear that we are not doing enough,” said Adrian Gombart of the Linus Pauling Institute in a statement. “We strongly encourage public health officials to include nutritional strategies in their arsenal,” in addition to the messages about handwashing, social distancing and wearing masks.

Immune System Boosters
Several vitamins, minerals and fatty acids, such as vitamins C and D, zinc and DHA, play key roles in aiding the immune system. The roles of vitamins C and D are particularly well known.

Vitamin C promotes the body’s production of many types of immune cells. It also helps maintain the structure and function of these cells. When faced with invading microorganisms, the immune cells release several toxins, including hypochlorous acid, that kill pathogens. A lack of vitamin C can make you more prone to getting sick.

Immune cells contain vitamin D receptors that affect their function, which means that vitamin D has a significant influence on your body’s response to infections. A deficiency of vitamin D is associated with an increased susceptibility to infection.

We need vitamin C daily because our body does not store it. Our body stores vitamin D, but few foods are good sources of the vitamin.

The Recommended Dietary Allowance (RDA) for vitamin C is 75 mg for women and 90 mg for men plus 35 mg more each day for people who smoke. To meet the RDA for vitamin D, adults need to consume 600 IU daily until the age of 70 when the RDA increases to 800 IU a day.

Multivitamin, mineral and fatty acid supplements, even in amounts that exceed current guidelines, can be a safe, effective and inexpensive way to help our immune systems fight off COVID-19.

The biggest issue is that people just aren’t getting enough of these nutrients in their diets, and that could destroy our resistance to infections, Gombart explained. A poor diet can lead to an increase in disease and all of the extra burdens that go along with it.

“The present situation with COVID-19 and the number of people dying from other respiratory infections make it clear that we are not doing enough,” said Gombart, in a statement. “We strongly encourage public health officials to include nutritional strategies in their arsenal.”

In addition to eating a well-balanced diet, the researchers advise taking a daily multivitamin/mineral supplement, consuming 200 milligrams (mg) or more of vitamin C daily, along with 2,000 international units (IU) of vitamin D and 250 mg of the fatty acids EPA + DHA. These numbers are higher than the RDA for vitamins C and D, and there is no RDA for fatty acids at this time.

You can easily boost your intake of vitamin C with food. Citrus fruits, orange juice, red and green sweet peppers, broccoli, strawberries and Brussels sprouts are particularly good sources of vitamin C. However, if none of these foods appeals to you, a 200 mg supplement may be advisable.

Much of our vitamin D comes from sunlight exposure; however, many may be deficient right now since winter is just ending and much of the world has been largely quarantined at home for the last few months. Fatty fish and other seafood add a good amount of vitamin D to our diets as does fortified milk. Now that the weather is warming up, you can hopefully increase your vitamin D levels by spending time outdoors.

Be aware that large doses of vitamins and minerals can be harmful, so tolerable upper limits (UL) of safety for these nutrients have been set.

Taking a vitamin/mineral supplement may not be advisable for those with certain health conditions and because interactions with prescription medications are possible. If you fall into this category, talk to your doctor.

Be aware that large doses of vitamins and minerals can be harmful, so tolerable upper limits (UL) of safety for these nutrients have been set. For vitamin C, 2000 mg is the UL and for vitamin D it is 4,000 IU.

If you choose to take supplements, be sure to add the amounts of vitamins delivered in a multivitamin/mineral supplement to those in a single nutrient supplement so you don’t exceed the UL amounts.

The most important advice is probably to do what you can to improve your diet and lifestyle so that you obtain the nutrients you need without relying on supplements. Food is always the best way to get the nutrients your body needs, but if that is not possible, use supplements wisely.

These findings are published in Nutrients.