From the start of the coronavirus pandemic, there has been a focus on wellness, and ways to avoid becoming seriously ill. One of the methods people are relying on is taking vitamins targeted to bolstering immunity.

In a rush to buy necessities, both orange juice and vitamin C supplements have seen sales spiking at the grocery store. Orange juice purchases jumped approximately 10% in March, and frozen orange juice sales increased by 27%, NPR reported. Large vitamin distributors have also reported a shortage of supplements targeted to boosting immunity. It’s estimated that sales of vitamin C skyrocketed 146% around the time more news of the pandemic emerged in the U.S., according to a report from the New York Times.

But with no firm evidence that vitamin C can prevent coronavirus, is there any reason to supplement? Can you strengthen your immune system more generally using supplements or advanced nutrition? Here’s what experts say.

You can boost your immune system to help fight off infections ...

According to Michael Roizen, chief wellness officer for Cleveland Clinic, strengthening the immune system is generally a reasonable goal.

When the coronavirus enters your system, in this instance, your body will almost immediately recognize the antigen (aka the virus) as foreign. When this happens, certain cells send up a signal to make antibodies to fight it off. We create these antibodies, the most common of which is called IgG, hoping they will “provide us immunity by neutralizing the invader,” Roizen said. 

Ideally, you want the IgG, or the neutralizing antibodies, already present when an antigen comes in and sets off the immune response. Unfortunately, though, this isn’t always the case.

This is where enhancing the body’s preparedness for unwelcome invaders could come in; a healthy immune system can be a great defense ― and you can take steps to bolster it, according to experts. Even if you’re getting a vaccine, like the flu shot, healthy habits can help increase the “take” or “success” of the shot, Roizen said. Sleep, getting good nutrients and exercise are all part of that.

... But you don’t necessarily need supplements, and they won’t protect you from COVID-19.

Nutritional compounds like vitamin C, antioxidants and zinc do “work with our immune system and help it function more effectively,” said Lona Sandon, an associate professor in the department of clinical nutrition at the University of Texas Southwestern Medical Center. “But if you are already getting them from food, evidence and research does not promote the need to take more.” 

And, most importantly, there’s scant evidence to support taking supplements to prevent COVID-19, according to Sandon. For instance, one review of vitamin D showed no link between a deficiency and likelihood of contracting the illness; supplementing didn’t seem to help treat or prevent COVID-19 either. The National Foundation for Infectious Diseases said there’s “no evidence” that loading up on vitamin C will prevent a coronavirus infection. Even Harvard’s T.H. Chan School of Public Health stated there was no direct evidence for or against certain nutrients to treat or prevent COVID-19, though there is evidence nutrition may bolster immunity in other ways. 

It’s OK to take a daily multivitamin (but it should come at the recommendation of your doctor). Just don’t take “extra” or more than a regular dose, Sandon said. It certainly won’t make you any more immune to the coronavirus.

In fact, there’s a ceiling to how much your body can manage at any one time. If you take a multivitamin, it covers your daily dose of B vitamins, vitamin C and other minerals, so stop there.

“Don’t take a multivitamin and a bunch of other things, like vitamin water or extra B vitamins,” Roizen said, adding that too much of a vitamin can be dangerous.

Instead, spread out your daily dose if you take one. Roizen suggested splitting a multivitamin in two and staggering it throughout your day.

“Take a half a multivitamin in morning and in the evening,” he said. “You urinate out the water soluble components within 12 hours or so, so to keep a steady level, take part of it in the morning and the other part at night.” 

There are some cases in general where an added supplement to your daily multivitamin could help, Roizen said. Just don’t expect them to rid you of any specific disease, and make sure to talk to your doctor first. He recommended DHAfor immunity, noting there’s evidence to show the fatty acids can reduce the symptoms associated with upper respiratory infections.

“You can take 900 milligrams a day, or get it through three six-ounce portions of wild salmon a week,” he said. You also can add vitamin D if you are not able to get outside enough while sheltering in place, but just 1000 IU or 2000 IU. (Again, your physician will know what to recommend based on your health history and previous bloodwork.)

But mostly, focus on what you put on your plate; balance is important for combatting most infections.

“It comes back to basic nutrition and common sense,” Sandon said. “Start with a healthy baseline diet, and if you cannot get your needs met in some way, maybe you do need a vitamin.” 

Sandon said to focus on the healthy building blocks of your immune system.Vitamin B6, found in whole grains, nuts and legumes, allows your body to make antibodies. Lean protein, like skinless chicken and fish, can help as well. Vitamins A, C and E are also critical components of healthy immune function, and are plentiful in lean proteins, fruits and vegetables like sweet potatoes, leafy greens, oranges, carrots, nuts and seeds.

What you should do about vitamins if you get sick.

According to Sandon, any time “we become sick from viral or bacterial infection and there’s a fever,” we may need a little extra nutrition, like vitamin C and protein.

For instance, people in the ICU, where their body is working extra hard, may benefit from extra vitamin C supplementation and there is evidence for that, she said. “When someone is in that situation, they use up their vitamin C stores more quickly,” she added.

For the average person at home, a few dietary tweaks will suffice. 

“Usually you can accomplish this by eating a little more,” she said. “You could get this through supplements, but if you just have a light touch of illness, and are eating a balanced diet of lean protein, nuts, seeds and root vegetables, you typically won’t come up short.”

If you’ve been sick for a week or two, and you’re generally not eating well, you might feel better consuming a nutrient-packed drink, so you can get the nutrients along with your daily calories, Sandon said.

“[Supplements are] not coming with the calories, healthy fats and proteins. You still need macronutrients,” she added.

The research on the efficacy of upping your vitamin intake when you’re sick is somewhat mixed. Roizen said there’s some evidence to suggest increasing zinc and vitamin C when you’re sick from your normal daily requirement may help shorten the duration of a cold respiratory illness; other reports show that it isn’t a miracle worker.

If you do increase your dosage of zinc and vitamin C, you should only do so during the period you are experiencing symptoms, and that’s it, Roizen said.

“With zinc and vitamin C, you can have side effects if you take too much,” which can include nausea, vomiting, abdominal cramps and headache, among other symptoms. Consult with your doctor before taking or increasing a dose of either of these supplements. 

Beyond that, really focus on general wellness. Get sleep, seven or eight hours per night. Take breaks during your day, exercising however you can. Soak up the sun for adequate vitamin D, in lieu of supplements if you can. These are the critical building blocks of, not just immune function, but overall health.

Please Note:

Experts are still learning about the novel coronavirus. The information in this story is what was known or available as of press time, but it’s possible guidance around COVID-19 could change as scientists discover more about the virus.

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