- Doctors warn that relying on supplements — and taking too much of them — may do more harm than good.
- Many vitamins and minerals can impact overall immunity but no single one can solely influence immunity.
- Want to add a new supplement? Talk about it with your doctor.
Experts continue to encourage people to eat well and exercise during the COVID-19 pandemic. Meanwhile, reports claiming that supplements can prevent or treat COVID-19 have emerged.
Doctors warn that relying on supplements — and taking too much of them — may do more harm than good. Still, vitamin C, D, probiotics, and zinc continue to fly off the store shelves. Is there a role supplements can play in our health as the virus continues to spread?
“Everybody’s desperate,” Jon C. Tilburt, MD, a physician at Mayo Clinic, told Healthline. “It is understandable that patients want to do whatever they can to prevent getting or spreading the virus.”
Melissa Majumdar, RD, LDN, a nurse and spokesperson for the Academy of Nutrition and Dietetics, said that any product saying it can prevent or cure coronavirus is violating federal standards.
“There is no supplement or herb that can prevent or cure coronavirus,” Majumdar said.
Many vitamins and minerals can impact overall immunity but no single one can solely influence immunity, she added.
“Vitamins A, D, C, zinc, and iron are most known for their roles in the immune system,” she said. Instead of taking additional supplements, focus on other aspects of supporting your immune system such as exercising, hydrating, getting enough sleep, and getting enough fruits and vegetables.
There are several relatively safe supplements such as zinc that “may be safe to try,” Tilburt concurred. None are proven, and they are not a substitute for public health measures, he said.
“Nasal zinc sprays can cause loss of smell. That can be permanent,” noted Beth Kitchin, PhD, a registered dietitian, nutritionist, and assistant professor at the University of Alabama at Birmingham.
Frank Romanelli, PharmD, a professor at the University of Kentucky, said some reports have said zinc can have some antiviral effects, and that vitamin C may help with the respiratory syndrome associated with severe COVID-19 infection, but this is all anecdotal.
As for people loading up on “safe” vitamins and minerals, experts say they shouldn’t do it.
“Megadoses of vitamins can be dangerous. And they aren’t going to prevent or treat COVID or even shorten the duration of the disease,” Kitchin said.
If someone is truly deficient in a nutrient, getting themselves up to a healthy level may help support the immune system.
“But the idea that more is better is not only wrong, it can be dangerous,” Kitchin added.
Colloidal silver is another supplement that’s been in the spotlight since the outbreak. It can disinfect surfaces but you should not ingest it, as the mineral can cause the skin and whites of the eyes to turn a permanent grayish color, Kitchin added.
A few supplements that are not vitamins or minerals but said to be immune boosters, pose similar risks.
“There are some test tube studies suggesting its immune-boosting effects may be problematic for a coronavirus situation, so I would not feel comfortable recommending,” he said. “Elderberry can interact with immunosuppressants, so I would be fairly cautious even trying it if the person’s taking prednisone for medications for a transplant or cancer.”
There has been some concern that elderberry supplements have played a role in actually worsening the damage to the lungs in severe cases of COVID because of a “cytokine storm,” which occurs when the immune system overreacts, Kitchin said.
“There’s nothing definitive but since there’s no good data to support taking elderberry, I’d avoid it right now,” she added.
Some evidence has shown echinacea can provide support during a cold, but people must remember that COVID-19 is not the common cold, Majumdar emphasized.
Some people have been trying to drink tonic water that contains quinine. The medicine is distantly related to hydroxychloroquine, the antimalarial drug being tested to treat COVID-19.
“Exaggerated amounts of any chemical — even water — can be harmful,” Romanelli told Healthline. “If patients do not have a good reason to be using any supplement then they should in general avoid them.”
Adding a new supplement? Talk about it with your doctor, Tilburt advised. Watch for interactions with prescriptions and remember that “natural” does not mean the supplement is risk-free, he said.
“There is no magic bullet to preventing COVID-19 with diet or supplements,” added Sharon Palmer, a registered dietitian nutritionist from California. “You can do the most to support your immune health with a diet filled with nutrients that are functional in immune defense, such as vitamins C, D, E, and zinc.”