We have known for a long time that nutrition is intricately linked to immunity. A good diet keeps your immune system strong and decreases the risk and severity of illness.
But should you be taking a supplement?
While there is no proof that supplements help to prevent COVID-19, we do know that low levels of certain nutrients can decrease your immune systems ability to fight the virus. Food is the first source, but supplements may need to come in when a deficiency is suspected. This may be the case for those who are not careful about their food choices and older people who eat scant, unvaried diets.
Adequate levels of zinc, vitamin C and vitamin D have the strongest support in keeping the immune system strong. This is based on studies of previous coronaviruses, like the common cold. We know these nutrients reduce a virus’s ability to enter the cell, attach, or replicate, and by reducing inflammation.
Here’s a closer look:
Zinc boosts the production of antibodies. Taking zinc within 24 hours of the first sign of a cold can shorten the severity and duration of a cold. We know low levels of zinc limit the ability to mount an adequate immune response to infections.
The WHO reported that zinc deficiency may be responsible for 13% of all lower respiratory tract infections, most often pneumonia and flu, in children younger than 5 years.
Researchers think that zinc deficiency may be one of the reasons seniors are more susceptible to infections.
The recommended dietary allowance for zinc is 8 mg for women and 11 mg for men. Meats, seafood, dairy products, nuts, legumes, and whole grains offer relatively high levels of zinc. The dose of zinc in studies showing protection ranged from 20 mg/week to 92 mg/day, suggesting dose is not the critical factor, which means a multi-vitamin is likely to contain an adequate amount of zinc to meet the need.
Don’t go overboard, as the likelihood is that nutrients may only play a role if
you’re deficient. VITAMIN D can lower the odds of developing acute respiratory tract infections by 12% to 75%. Studies show flu symptoms are fewer and recovery earlier in those who receive doses of vitamin D greater than 1000 IU.
A just-published study in the journal Aging Clinical and Experimental Research, found a correlation between low vitamin D levels and higher rates of COVID-19 infections and — even more so — COVID-19 deaths among residents of different European countries.
Why does vitamin D help? Maintaining adequate levels of vitamin D boosts the protective properties of antimicrobial compounds in white blood cells, which enhance the body’s defense against viruses.
Since it’s hard to get sufficient vitamin D from the food we eat, it makes sense to supplement.
Many of the commonly available multivitamin/multimineral supplements contain 1000 or 2000 IU of vitamin D, which is a good target. Americans with dark skin may require more – up to 4,000 IU which is still considered safe.
We can also get Vitamin D from sunlight. For more detail on how sunlight and vitamin D interact with COVID-19, read this.
Vitamin C is also key. It acts as an antioxidant, which limits inflammation and tissue damage. Like zinc, sufficient vitamin C levels have been shown to reduce the incidence of respiratory tract infections.
It makes sense to include good food sources of vitamin C – citrus fruits, tomatoes, red and green peppers, kiwi, broccoli, strawberries, Brussels sprouts, cantaloupe and potatoes. Eating these fruits and veggies should ensure adequate vitamin C for healthy people. A small study is looking at high doses of vitamin C which appear to decrease the time on a ventilator for seriously ill people with COVID-19. The dose used in these studies varied from 1-3 g/day. Doses of vitamin C above 2 g/day should be avoided outside of medical care. Remember, more isn’t always better.
A good multivitamin is not a bad idea, and may be easier than taking separate pills, particularly for those at a higher risk of COVID-19. For a guide to help you choose the right one for you, Nutrition Action health letter provides an excellent review of the many choices. v
But keep in mind, a good diet not only keeps your immune system strong, but protects your overall health.
That is Smart Eating!
