Does Taking Vitamin C Supplements Prevent the Common Cold?

taking vitamin C

Grab a box of tissues – cold season is on its way. I don’t know about you, but I hate having a runny nose or a stuffy head! Although the common cold won’t kill you, it can make you pretty miserable for a few days.

With the threat of colds increasing as cooler weather approaches, you want to do what you can to keep pesky head colds at bay, Yes, you should do the common sense stuff like washing your hands more enough but that’s not always enough.

What do some people do in hopes of warding off a cold? They grab a bottle of vitamin C and pop a few – but does taking vitamin C supplements really lower the risk for catching a nasty cold virus – or is it a waste of time?

Blame It on Linus Pauling

You’ve probably heard of Linus Pauling. He was a brilliant man – one who won not one but two Nobel prizes. Few people have had that honor. He was also a science prodigy who knew biochemistry and how vitamins work like the back of his hand. It was Dr. Pauling, back in the 1960s, who proclaimed that vitamin C prevents the common cold.

Pauling, the world’s greatest proponent of vitamin C supplements was actually a PhD and not a practicing physician, but he did more to raise awareness of vitamin C than any other scientist or doctor.

Dr. Pauling recommended taking 1,000 milligrams of vitamin C daily to reduce the risk of colds by half. Keep in mind the RDA is only 60 milligrams.

Linus Pauling himself supposedly took an unbelievable amount of vitamin C – 12,000 milligrams daily. Dr. Pauling not only believed vitamin C could prevent the common cold but it also might be effective for prevention and treatment of cancer.

He also believed atherosclerotic heart disease, the most common form of heart disease, was caused by a vitamin C deficiency and that high doses of vitamin C could prevent it.

By this time, you’re probably wondering how old Linus Pauling was when he died and what he died of. He perished of prostate cancer at the age of 93. Pauling reportedly claimed that it was vitamin C that kept his prostate cancer in check so he could live into his 90s although there’s no way to prove that.

Vitamin C and Colds

It’s not necessarily a stretch to assume vitamin C might be protective against colds. Vitamin C is an antioxidant vitamin that helps protect cells against free radical damage, the destruction that happens when cells are exposed to oxygen, and essentially causes cells to “rust.” Scientists believe free radical damage plays a role in a variety of diseases and is a contributor to aging.

Vitamin C also supports healthy immune function. This partially explains why Linus Pauling believed vitamin C could prevent colds. You need a healthy immune system to fight off cold viruses. Was he right?

What Science Shows So Far about Taking Vitamin C for Cold Prevention

Back in the 1970s, a small study supported Dr. Pauling’s belief that vitamin C wards off colds. This study found kids living at a skiing camp in the Swiss Alps who took 1,000 milligrams of vitamin C daily had fewer colds than a placebo group who didn’t.

Unfortunately, Swiss children living in the Alps is a pretty narrow segment of the population and it’s hard to generalize results like that to the population as a whole.Since then, study after study has looked at whether or not vitamin C prevents colds with inconsistent results.

Although not consistent, the evidence as a whole, suggests Linus Pauling was wrong and if there is a benefit to taking vitamin C for cold prevention, it’s small.

But wait! Before you assume that vitamin C is worthless, there may be a small benefit to getting higher doses of vitamin C when you feel the symptoms of a cold coming on. A study carried out in 2010 found participants taking vitamin C daily had less severe cold symptoms but only if they started taking vitamin C prior to developing cold symptoms.

According to some studies, taking vitamin C may also reduce the duration of the common cold by a day or two. Where vitamin C might be the most useful is after exposure to unusual stress or cold exposure.

For example, some studies show supplementing with vitamin C before and after extreme physical exertion, like running a marathon, DOES lower the risk of developing a cold by up to half. So, if you have a marathon in your future, it might be smart to increase your vitamin C intake.

Is It Safe to Take High Doses of Vitamin C?

Before taking a supplement, weigh the pros and cons. Most importantly, “do no harm.” Vitamin C is a water-soluble vitamin, meaning you eliminate excess amounts in your urine. That’s why you hear people say you’re creating expensive urine when you take certain supplements.

Despite the fact that your body can self-regulate vitamin C by eliminating the excess, high doses of vitamin C can overwhelm the system and potentially lead to side effects, the most common of which are stomach cramps, nausea, and diarrhea.

Vitamin C supplements also increase the risk for kidney stones, a particularly painful condition to have.

Vitamin C as a Pro-Oxidant

There’s also evidence that high doses of vitamin C can cause a more serious type of damage. Remember how we said vitamin C is an antioxidant that protects against cell damage? Some research suggests that at high doses it can have the opposite effect – it can actually cause free radical damage to cells.

How can it do both? Researchers at Mount Sinai School of Medicine found vitamin C at higher doses can convert iron in your body to a form that causes free radical damage to cells and tissues.

Plus, vitamin C increases iron absorption from the foods you eat. This can potentially increase iron stores in your body, which isn’t healthy beyond a certain point. Iron at higher levels can damage your liver and other tissues as well.

As you can see, the potential downsides to taking vitamin C supplements are greater than the benefits of doing so. There simply isn’t enough evidence that vitamin C prevents colds.

Even if it does shorten the duration of colds or lessen the symptoms, the benefits aren’t dramatic. When you weigh the benefits and downsides, the scales tip strongly towards not taking high-dose vitamin C.

The Smart Approach to Getting Enough Vitamin C

The RDA for vitamin C is 60 milligrams per day. You should get at least that much, and the safest way to get it is through diet. It really isn’t hard to meet your vitamin C requirements through diet.

Did you know eating a whole papaya supplies more than double your daily requirement for vitamin C? Other top sources of vitamin C in descending order include:

  • Bell peppers
  • Broccoli
  • Brussels Sprouts
  • Strawberries
  • Pineapple
  • Oranges
  • Kiwifruit
  • Cantaloupe
  • Cauliflower

One caveat: Cooking foods destroys a significant amount of the vitamin C in foods. So, cooked vegetables aren’t the best way to supply your body with vitamin C. Make sure you’re including some raw foods in your diet. Top your salads off with raw broccoli, cauliflower, and bell peppers and make sure you’re eating at least one piece of whole fruit daily.
Papaya is an excellent source of vitamin C

Does Vitamin C Have Anti-Aging Benefits?

Beyond its limited use as a cold remedy, can vitamin C slow down the aging process? One area where vitamin C does have anti-aging benefits is for your skin.

A number of studies show vitamin C reduces wrinkles and areas of increased pigmentation, problems we see more of as we age. It also boosts production of collagen, the support structure that helps keep your skin firm.

As the Paula’s choice explains, “vitamin C reduces skin discolorations, strengthens the skin’s barrier response, enhances skin’s repair process, reduces inflammation, and helps skin better withstand exposure to sunlight, whether protected by sunscreen or not.”

Hint: If you buy a vitamin C skin cream, always choose one in a dark container and keep it away from light and heat. In our opinion, vitamin C does have anti-aging benefits when you apply it to your skin.

The Bottom Line

No doubt about it – vitamin C is an essential vitamin. Before scientists understood its function, people who didn’t eat fruits and vegetables died from scurvy. Fortunately, you never have to suffer that fate.

Based on what we know now, we don’t recommend taking a vitamin C supplement, consider taking one for a few days if you’re running a marathon or will be exposed to unusual physical stress, you might want to at least double the amount of vitamin C you get through diet or take a supplement short-term.

If that’s not the case, we recommend eating more raw fruits and vegetables to meet your vitamin C requirements. Unless you’re a salad lover, you’re probably not eating many raw foods.

Tips for Getting More Vitamin C

  • Add berries to hot cereal.
  • Add one piece of fresh fruit to your lunch bag.
  • Eat at least one salad a day with raw veggies. Include broccoli, cauliflower, and red bell peppers. Kiwi too!
  • Dip raw veggies into your favorite dip instead of potato chips.
  • Blend up a green smoothie.
  • Add fresh fruit to yogurt for a high-protein, vitamin C-rich breakfast.

Finally, don’t forget to join us on Facebook for more tips, recipes, and inspiration. Feel free to post your question there too. 


Quack Watch. “The Dark Side of Linus Pauling’s Legacy” Stephen Barrett, M.D.
Int J Vitam Nutr Res. 1997;67(5):329-35.
Cochrane Database Syst Rev. 2013 Jan 31;1:CD000980. doi: 10.1002/14651858.CD000980.pub4.
Medscape Multi-Specialty. “Vitamin C Cures the Common Cold: Fact or Fiction”
NY Times. “Taking Too Much Vitamin C Can Be Dangerous, Study Finds”
World’s Healthiest Foods website.
Dermatol Surg. 2002 Mar;28(3):231-6.

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Kristie Leong M.D.

Dr. Kristie Leong and Dr. Apollo Leong are physicians helping you to lead a healthy lifestyle by sharing nutrition and fitness tips and keeping you abreast of the latest health news.