Recently the National Institutes of Health (NIH) released a fact sheet regarding dietary supplement usage for COVID-19 protection. Currently by law, no supplements can legally claim that they are a treatment, prevention, or cure of any disease, and this includes COVID-19. However, many people are still purchasing and using dietary supplements to prevent or treat COVID-19.
People who are deficient in vitamin C, vitamin D, and zinc have been shown to be more susceptible to infections (like colds and flu) because these nutrients are needed for the immune system to work. Scientists believe people deficient in these nutrients may also be more susceptible to COVID-19 infection. However, we currently don’t have research to know if any supplement is helpful for Covid-19.
Here is an overview of the NIH review of these supplements:
Vitamin D
It is an essential nutrient for our bodies and is not found in a lot of foods, however most people obtain their needed vitamin D through fortified milk and dairy products, or other fortified foods. It can also be naturally produced in the body from sun exposure. Individuals who live in the areas of low sun exposure and individuals who do not consume dairy products or animal products tend to have a higher risk of vitamin D deficiencies. In immunity, it has been shown to suppress inflammation, decrease viral replication load, and increase T-cells. Individuals with vitamin D deficiencies have been shown to be more likely to have COVID-19. Being vitamin D sufficient has also been shown to decrease COVID-19 severity. More clinical trials are being run to confirm the benefits of vitamin D.
Vitamin C
Vitamin C, like vitamin D is an essential nutrient. Vitamin C can be found in citrus fruits, potatoes, tomatoes, and many other fruits and vegetables. Most individuals do not have vitamin C deficiencies. It helps in our immune system through antioxidant effects and may inhibit viral replication. Research has found that supplemental vitamin C may enhance immune function when an individual’s vitamin C status is lower than normal there is currently no sufficient data to support that vitamin C supplementation can prevent or treat COVID-19.
Zinc
Zinc is in a variety of food ranging from beef and pork to whole grains and dairy. It has anti-inflammatory and anti-viral properties, and helps us maintain our tissues which provide a barrier to infections Deficiencies can lead to poor immune response and increased susceptibility to infection-especially in the lungs. Evidence has shown that zinc might help shorten the duration of the common cold but research does not yet support the use of zinc supplements to treat or prevent COVID-19.
Final takeaway
There is not strong enough proof that any supplement can fully prevent or better the symptoms of COVID-19. However, deficiencies in some essential vitamins and minerals may make you more susceptible to infection, including the upper respiratory infection of COVID-19. It is best to talk to your health care provider to see if you are at risk of any nutrient deficiencies, and to make sure you eat an overall healthy diet.
If you would like to learn about more supplements, this fact sheet is available from NIH.