It’s still unclear how the new coronavirus affects the body, so scientists and doctors have many more questions to answer. Social distancing and washing hands frequently with water and soap are recommended to prevent the virus from spreading.

But, people are wondering if there’s anything else they can do to boost their immune system in the prevention and fight against the virus. In particular, are there any supplements that can be helpful?

When it comes to COVID-19, there’s no evidence of how a specific supplement can help the immune system defend you against it. According to microbiologists studying the immune system, globally boosting it or increasing it to be on high alert to protect against every possible germ is not very useful, says the professor of microbiology at Harvard Medical School in Boston, Michael N. Starnbach.

Dr. Starnbarch explains that the immune system recognizes foreign substances and ensures they are eliminated from the body, but those responses and cells are finely tuned. So, if your immune system is on high gear or overly active, it may attack your own healthy tissues. This is exactly what happens in Crohn’s disease, rheumatoid arthritis, and other autoimmune diseases.

Dr. Starnbarch points out that supplements have so far proven to be effective in boosting the immune system only in malnourished populations. But, this is rarely the case in the U.S. A serious malnourishment can make people more prone to diseases, but this doesn’t mean that getting higher amounts of nutrients and vitamins they need will make their immune system stronger or more effective.

The president and founder of Consumer.Lab.com, Tod Cooperman, MD, says that vitamins and supplements may lower the risk of respiratory viruses or shorten their duration, especially if they have some deficiency. It’s still unknown whether these vitamins and supplements would affect the new coronavirus the same way.

Dr. Cooperman says that what you can do for now to protect from COVID-19 is ensuring you’re not deficient in any vitamin by taking a basic multivitamin every day. Other things you can do to keep your immune system strong is exercise, get enough sleep, and eat well.

Research on how zinc affects other viruses may suggest it can reduce the severity of symptoms. So, Cooperman recommends taking zinc lozenges if you start noticing symptoms of the coronavirus or any other virus to help coat your throat. Still, there’s not enough research to prove these effects.

What Experts Know About Supplements for Now

The integrative medicine doctor at Cleveland Clinic in Ohio, Yufang Lin, MD, says that the evidence they have about supplements suggests that some of them may help lower infection or its duration.

However, there’s not enough research to prove that supplements can prevent you from catching a pathogen in the first place. Also, there’s no such thing as one supplement for boosting the immune system in the fight against all threats.

Plus, COVID-19 is a completely new threat, so there’s still no evidence of how specific supplements or vitamins can help prevent it. According to Dr. Lin, it’s not even known whether they can help support the immune system in the fight against it.

However, here’s what researchers know for now:

Elderberry

A 2019 study published in the Journal of Functional Foods suggests that elderberries contain compounds that can help prevent the flu virus from entering and replicating in human cells, as well as boosting the immune system in the fight against the virus.

So, elderberry taken in lozenges, pills, gummies, or teas may help reduce the production of the flu virus and speed up the recovery process.

Zinc

There’s certain evidence that zinc can support the immune system in the fight against the common cold and infections. In May 2017, the journal JRSM Open published a study which suggests that zinc lozenges can reduce the time people are sick with the common cold by 30%. Namely, the lozenges didn’t contain salt citrate or citric acid.

However, there’s still no evidence about how zinc affects other viruses, including the new coronavirus. What these lozenges can do, however, is prevent the activity of the viruses in the throat when the infection begins to spread, thus reducing the symptoms.

That’s why Cooperman believes that sucking zinc lozenges, not chewing, as soon as you notice symptoms can be beneficial for your throat in keeping it coated with zinc. However, don’t take more than the recommended dose of the lozenges.

Vitamin C

According to Lin, this vitamin can be beneficial in treating colds, the common cold being a type of coronavirus. The Cochrane Database of Systematic Reviews published a study conducted on 11,306 people who took 200 mg of vitamin C a day to see how it affects the common cold.

It turned out that the vitamin doesn’t prevent the cold in adults, but it does shorten its duration by 8%. Another group of studies conducted on Army troops, skiers, and marathon runners doing heavy exercise in extremely cold conditions show that taking 200 mg vitamin C supplements a day can lower the risk of colds by 50%.

Still, Lin believes that the best way to get the necessary vitamin C is through diet and not supplements. According to the National Institutes of Health, the recommended daily amount of this vitamin for adults is 75-90 mg. For example, a half cup of Brussels sprouts contains about 50 mg of vitamin C, one green pepper contains 60 mg, and one orange contains 75 mg of this vitamin.

The Harvard Health Letter doesn’t recommend taking more than 400 mg of vitamin C a day, as any excess is eliminated from the body through the urine.

Vitamin D

Cooperman explains the importance of this vitamin for the immune system. The National Institutes of Health links the lack of vitamin D with frequent colds and flu. You get this vitamin mainly through sunlight, so the levels may drop during the winter. If you decide to take vitamin D supplements, take 15 to 20 mg or 600 to 800 IU.

In 2017, the journal BMJ published a meta-analysis of prospective trials which discovered that this vitamin lowers the risk of respiratory infections by 42% in those with vitamin D deficiency. It turned out that taking 300 to 4,000 IU a day was more effective than taking a high monthly dose.

The journal Clinical Infectious Diseases published a double-blind placebo trial which showed that large doses of vitamin D didn’t help prevent respiratory infection in 5,110 vitamin D deficient older adults.

Researchers didn’t find a reduction in the cases of acute respiratory infections in comparison with placebo.

So, Cooperman says that unless you have vitamin D deficiency, taking this vitamin won’t really help you.

Apple Cider Vinegar

According to Lin, there’s no evidence that apple cider vinegar boosts the immune system or helps you fight against infections.

Turmeric

Even though turmeric does provide certain health benefits, such as glucose control or cholesterol management, Lin says there’s no evidence that it can help fight against viruses. Still, the Journal of Clinical Immunology published a review that shows curcumin, turmeric’s active ingredient, does affect the immune response in some way.

Nevertheless, make sure your doctor is informed about all the supplements you plan to take or are already taking as they may cause side effects if taken with other medications.