Many supplements and natural remedies are being promoted to treat or prevent coronavirus (COVID-19). None have been definitively proven to prevent or treat COVID-19. However, some vitamins and minerals can help with coronavirus if you are deficient in these nutrients.
Vitamin D is an immunomodulatory hormone and is necessary for a properly functioning immune system. Some studies have shown that low levels of vitamin D are associated with an increased risk of COVID-19 infection. For example, an Israeli study found that persons with vitamin D levels below 30 ng/ml were 45% more likely to test positive for COVID-19, and 95% more apt to be hospitalized. Other studies, including a study of hospitalized COVID-19 patients in New Orleans, have shown that having adequate blood levels of vitamin D are associated with reduced severity of the disease. In addition, vitamin D deficiency is more common in African Americans, the elderly, and those with hypertension and diabetes – all of whom are at an increased risk for more serious outcomes from COVID-19.
You can maintain normal blood levels of vitamin D by getting small amounts of sun exposure three or more days per week and by consuming vitamin D-fortified foods such as milk and other dairy foods or by taking a vitamin D supplement. Consuming extremely high doses of vitamin D supplements are unnecessary and may even increase the risk of respiratory infections in some people.
Zinc supplements have not been found to help except in those people who are deficient in zinc. In those who were deficient, a supplement may lessen the likelihood of getting a respiratory tract infection. People who may be low in zinc are the elderly, who do not absorb zinc as well as younger populations, people who routinely take medications such as antacids and ACE inhibitors, and vegetarians. The recommended intake for most adults is 8 to 11 mg/day. Foods that are good sources of zinc include shellfish, organ meats, beef, pork, and chicken. Breakfast cereals and bars are typically fortified with zinc. Studies have shown that zinc lozenges can shorten the duration of a cold by killing cold viruses. But only zinc gluconate and zinc acetate have been shown to be effective. Zinc lozenges that do NOT contain citric acid are recommended since citric acid may bind with zinc ions, making them less effective. For this reason, foods and beverages that contain citric acid, such as citrus fruits, should not be consumed within one hour of taking zinc lozenges. People using zinc lozenges for a cold should follow the directions on the package for the amount and frequency of lozenges to use.
Vitamin C is essential for a healthy immune system and facilitate the absorption of iron in the body. The recommended daily intake of vitamin C for most adults is 75 to 90 mg/day. There is evidence that an intake of larger amounts of vitamin C can lessen the severity and duration of a cold if taken regularly prior to getting a cold. However, there is no evidence that taking high levels of vitamin C can prevent people from becoming infected with the coronavirus. Studies are currently underway to determine if high doses of vitamin C can reduce time on a ventilator for critically ill COVID-19 patients. For the average person, the best way to get adequate amounts of vitamin C is by consuming foods high in vitamin C such as oranges, orange juice, sweet peppers, tomatoes, and kiwi.
Potassium serves as a critical electrolyte in the body and is necessary for the nervous system, skeletal system, heart muscle, and for maintaining a normal blood pressure. Low blood levels of potassium (hypokalemia) are also associated with heart problems and hypertension (high blood pressure). Although there is no research to support that potassium prevents COVID-19, people hospitalized with COVID-19 frequently have low blood levels of potassium. Evidence suggests that potassium levels are low in COVID-19 patients because the COVID-19 virus utilizes the enzyme angiotensin 1 converting enzyme 2 (ACE2) to enter cells. (The ACE2 normally helps regulate blood pressure by adjusting sodium and potassium.) The coronavirus inactivates the ACE2 on the cell surface, causing the excretion of potassium.
Potassium is found in a variety of fruits, such as cantaloupe, bananas, and orange juice; and vegetables, such as beans, squash, and potatoes. The recommended daily intake for adults is around 4,500 mg, or 4.5 grams, and is easily obtained with the consumption of fruits and vegetables.
Potassium supplements should not be taken by people who are taking prescription medications such as ACE inhibitors and potassium-sparing diuretics without first consulting with their physician.
Be skeptical of products with claims to cure or prevent coronavirus. Just because a product has been shown to have antiviral effects in a laboratory does not mean that it will cure a virus in humans. Many products being promoted as preventing COVID-19 lack evidence from peer-reviewed studies in humans. For example, products such as cannabidiol (CBD) products which have been heavily promoted to prevent coronavirus, have no peer-reviewed studies showing that CBD can prevent or treat COVID-19 in humans. In fact, reputable studies with both animals and humans using CBD products have shown that those given the CBD products had more respiratory infections than those who received a placebo.
The most important way to avoid infection with coronavirus is to prevent exposure by following the CDC guidelines and to follow a healthy lifestyle which includes getting adequate sleep, regular exercise, and a diet with adequate nutrients, especially vitamins C and D. And remember, even vitamins and minerals, especially when consumed in amounts much higher than the recommended daily intake, have the potential to be toxic, can alter the absorption of other key nutrients, can impact the effectiveness of some medications, and can alter the results of blood tests.