The novel coronavirus (COVID-19) continues to spread across the globe in a situation that is constantly evolving. While the process of isolating COVID-19 and developing a viable vaccine is still ongoing, the Centers for Disease Control continue to primarily recommend safe social distancing along with proper hygiene practices to prevent the spread of the illness.
Researchers still have a lot to learn about the novel coronavirus. While the best treatment for coronavirus at this point is prevention, maintaining a strong immune system may help to lessen the severity of symptoms should you fall ill with the coronavirus. Read on to learn more about some common immune boosters for coronavirus.
Zinc is an essential mineral that is involved in numerous aspects of cellular metabolism, including protein synthesis, DNA synthesis, cell division, and the catalytic activity of over 100 different enzymes. It also supports healthy growth and development in pregnancy, childhood, and adolescence.1
As cellular growth plays an important role in wound healing and a normal immune response, zinc is necessary for a healthy immune system. Maintaining your zinc levels can support your natural immunities and help to encourage a speedy and efficient response to viral infections.
In one study, researchers found that increasing intracellular concentrations of zinc using zinc ionophores like zinc pyrithione effectively inhibited the replication of several RNA viruses, including influenza and poliovirus. The study found that increased having higher levels of zinc inhibited replication of the coronavirus associated with SARS (severe acute respiratory syndrome) in a cell culture.2
Zinc has been shown to be effective for other respiratory illnesses. A meta-analysis also identified seven randomized trials that looked at the effectiveness of zinc lozenges in reducing the common cold (a more common type of coronavirus). The results found that groups who used zinc lozenges had a common cold duration that was 33 percent shorter on average. This suggests that zinc may be helpful in supporting natural immunities against the common cold.3
The recommended dietary allowance for zinc is 11 mg per day for adult men and 8 mg per day for adult women.1 In the zinc lozenge meta-analysis, servings of up to 92 mg of zinc per day had about the same effect as servings of up to 207 mg of zinc per day.
Zinc is naturally present in a wide range of foods, including:
- Red meat
- Beans and nuts
- Whole grains
It is also often fortified in other foods, like breakfast cereals. However, if you think you need more zinc, supplements can help to take the guesswork out of how much zinc you get.
2. Vitamin C
Vitamin C, also known as ascorbic acid, is what most people immediately reach for when they have the common cold or flu. Vitamin C plays a wide range of roles in the body, from the synthesis of collagen, carnitine, and certain neurotransmitters to protein metabolism. Vitamin C is a powerful antioxidant that has also been shown to regenerate other antioxidants. Antioxidants help to neutralize free radicals, which are products of oxidation that can contribute to damage to the cells and DNA.
“Vitamin [C] has a powerful antioxidant effect in your body,” says Dr. Michael Lam, M.D. Dr. Lam also says that vitamin C “aids your body in forming and maintaining connective tissues, such as your skin, blood vessels and bones.” According to Dr. Lam, Vitamin C may also help to prevent heart disease, increase folic acid absorption, and reduce triglycerides and low-density lipoproteins, or “bad” cholesterol.
Vitamin C is also necessary to maintaining a healthy immune system.4 Hayley Cimring, R.D., a registered dietician and diet and nutrition specialist, says, “Vitamin C also increases the production of white blood cells which are key to fighting infections.”
Although there’s little evidence to suggest that high doses of vitamin C will reduce the incidence of the common cold in healthy individuals, some studies suggest that low levels of vitamin C can potentially make you more susceptible to the common cold which can be caused by milder strains of coronavirus.
In a meta-analysis, researchers identified studies in the United Kingdom involving vitamin C supplementation. The UK has shown generally low vitamin C intake, with men showing lower vitamin C concentrations on average than women. Researchers found that in four studies, vitamin C supplementation had no marked effect on the incidence of the common cold among British women. However, four studies involving male students and schoolchildren found a statistically significant reduction in incidence rates among those who had been supplemented with vitamin C. This suggests that vitamin C intake may have physiological effects on an individual’s susceptibility to common cold infections.5
The recommended dietary allowance for vitamin C is up to 75 mg per day for adult women and 90 mg per day for adult men. Lactating women can take up to 120 mg per day. Vitamin C is readily available in a wide range of foods. Most people know that oranges, grapefruits, and other citrus fruits contain vitamin C, but the vitamin is also available in red peppers, strawberries, and a wide range of green vegetables, like broccoli and brussels sprouts.4
Most people get enough vitamin C from their diets, but you may consider a vitamin C supplement if you believe you need more of it. The good news is that vitamin C is relatively safe. Thanks to its water-soluble nature, any excess or unused vitamin C is flushed out of your body naturally via your urine.
3. Vitamin D
Vitamin D is most often associated with supporting strong bones, which it does by helping with the metabolism and absorption of calcium. Without enough vitamin D, you may develop soft, brittle bones. “Vitamin D protects bones and teeth, boosts calcium absorption, and supports the immune system,” says Rima Kleiner, R.D. However, vitamin D is also necessary for proper nerve and muscle function, and your immune system requires regular vitamin D to fight off any foreign microbes.6
Low vitamin D levels have been linked to a dysfunctional immune system and a higher susceptibility to infection. Vitamin D deficiency may also contribute to increased autoimmune issues, including psoriasis and multiple sclerosis.7
Vitamin D is synthesized in the body when the skin is exposed to sunlight. Some studies suggest that the lack of sun (and thus generally low levels of vitamin D) in the winter is one of the components that may contribute to the seasonality of the flu. Vitamin D was shown to stimulate the expression of powerful antimicrobial peptides that exist in the epithelial cells that make up the lining of the respiratory tract.8
In one randomized controlled clinical trial, schoolchildren were provided with either a placebo or vitamin D supplements during the flu season from December 2008 to March 2009. Results of the study found that 10.8 percent of the children in the vitamin D group developed influenza A, compared to 18.6 percent of the placebo group. In children who had been diagnosed with asthma, more children experienced asthma attacks as a secondary outcome in the placebo group than in the vitamin D group. These results suggest that vitamin D supplementation during the winter may reduce the incidence of influenza A in schoolchildren.9
As mentioned, your body can synthesize vitamin D when your skin is exposed to direct sunlight. However, most of the vitamin D in the American diet comes from fortified foods, including orange juice, yogurt, milk, and some brands of breakfast cereal. Vitamin D can otherwise be found naturally in fatty fish, mushrooms, and beef liver.6
Elderberry is a well-known immune booster and natural remedy used for upper respiratory tract infections. In folk medicine, elderberry has commonly been used to treat the cold, flu, and sinusitis, and it may reportedly have antiviral properties.
In a randomized study, 60 patients with flu-like symptoms for 48 hours or less were given a placebo syrup or a syrup containing elderberry. Results of the study showed symptom relief about four days earlier on average in those using the elderberry extract. Those who were given the elderberry extract also used rescue medications significantly fewer times than those who were given the placebo. This suggests that elderberry extract is safe, efficient, and cost-effective and may help to reduce the length and severity of the flu. However, larger studies are necessary to confirm these findings.10
More research is also necessary to understand the mechanisms at work, but elderberry is known to contain high levels of vitamin C, antioxidant flavonols, and anti-inflammatory anthocyanins.11
Probiotics refer to the beneficial bacteria that exist in the gut. These beneficial bacteria play an important role in various aspects of your health, including digestion, metabolism, and even your general mood and mental health. Probiotics may also contribute to a healthy immune system. Studies show that probiotics may regulate the immune response via the functions of the systemic and mucosal immune cells and epithelial cells in the intestines, which may help in various immune-related diseases, including eczema, allergies, and viral infections.12
In a meta-analysis, researchers identified 10 studies involving the effects of probiotics on the common cold. The results of these studies found that probiotics had a marginal effect on preventing the common cold and a modest effect on reducing cold symptoms.13 The optimal dosage for these effects still requires further study, though most experts recommend taking a probiotic supplement containing at least 10 billion CFUs.
“Yogurt is a fermented food that naturally contains lots of probiotic cultures,” says Cimring, “These cultures help to increase the good bacteria in your gut and stimulate your immune system to help fight diseases.” Along with yogurt, Dr. Mary Sawdon, M.D., N.D, recommends consuming kefir and kimchi for their probiotic content.
Protecting Yourself from COVID-19
On top of boosting your immune system, protecting yourself from COVID-19 often comes down to simple practical measures.
- Wash your hands frequently, especially after you have been in a public place or coughed or sneezed into your hand. Use soap (it does not have to be antibacterial) and water, foaming up all parts of your hands for at least 20 seconds.
- If soap and water are not immediately available, use a hand sanitizer containing at least 60 percent ethanol (alcohol).
- Avoid touching your nose, mouth, and eyes if you haven’t just washed your hands.
- Disinfect commonly touched surfaces regularly. This includes doorknobs, phones, keyboards, and tables. The good news is that the coronavirus is relatively easy to neutralize. Just one minute of exposure to 0.1% exposure to household bleach, 0.5% hydrogen peroxide, or 70% ethanol is enough to completely inactivate coronaviruses.14
- Practice social distancing. Avoid close contact with those who are sick, but remember that some people may have the virus but show no signs or symptoms. That means that you could be a carrier without even knowing it. Stay home as much as possible and keep a distance of at least six feet from other people, especially those who are at a higher risk, including the elderly and the immunocompromised.
- Wear a face mask when going out in public. Face mask usage has been proven to decrease spread of the flu and coronavirus. Only grab the face mask via the elastic straps to minimize contact with your nose and mouth, and immediately place your cloth mask into your laundry basket after use.
The “novel” part of the novel coronavirus means that no one has a natural immunity to COVID-19. However, supporting your natural immune system (while also practicing the CDC’s recommendations) may help to protect you from COVID-19.