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Vitamin C and the Common Cold: Will Ascorbic Acid Help?

Why does modern medicine argue against ascorbic acid for the common cold. You might think vitamin C is worthless. It is essential. Learn why!

One of the most contentious issues in modern medicine revolves around vitamins, especially vitamin C (aka ascorbic acid). For reasons that mystify us, most health professionals dismiss the value of vitamin supplements in general and vitamin C in particular. For decades, we have been reading that all you need is a well balanced diet. Given that Americans love for quick and easy processed food, that’s not as easy as many health professionals seem to think. There are only four people who have won the Nobel Prize twice. Linus Pauling is one of them. He was the strongest advocate for increasing intake of ascorbic acid.

So Many Cold Viruses and No Drug Treatments

It’s that time of year. People are starting to sniffle, sneeze, cough and complain. Trying to figure out which virus is responsible for the misery is virtually impossible. Although the FDA has approved rapid tests for COVID-19 and influenza, there are literally hundreds of other viruses that cause upper respiratory tract symptoms.

Scientists have identified more than 160 rhinoviruses and several coronaviruses that can produce cold symptoms. That doesn’t count parainfluenza virus, adenoviruses, enteroviruses or respiratory syncytial virus (RSV). We do not understand why modern medicine has been unable to develop tests to quickly distinguish between all these different infectious agents. And more to the point, why don’t we have effective treatments?

None of the drugstore cold remedies do anything to speed healing. And one, phenylephrine (PE), has been shown to be ineffective as an oral decongestant. There are even questions about the benefits of standard cough suppressants, fever reducers or pain relievers. Most colds don’t cause a lot of pain.

Lowering a modest fever may interfere with the body’s natural immune response. You can learn more about the body’s natural virus-fighting strategies and why a moderate fever is protective at this link. Dr. Roger Seheult will tell you why a controlled fever could be beneficial and how steam inhalation might also be helpful.

This reader wants to know how to boost immunity:

“I am suffering pretty classic cold symptoms and would like to take something that would enhance my immune system. Are there any natural remedies that I could order online so I don’t have to browse the health food store?”

Vitamin C Against Cold Symptoms:

Vitamin C may be one of the oldest cold remedies. It was popularized in the 1970s by Nobel Prize winner, Dr. Linus Pauling. We still have a copy of Dr. Pauling’s book, Vitamin C and the Common Cold (W.H.Freeman and Company, San Francisco, 1970).

Here is what Dr. Pauling wrote over 50 years ago:

“I mentioned in the Introduction my decision to try to resolve the apparent contradiction between the opinion expressed by authorities in nutrition and my own experience, which supported the widely held belief that ascorbic acid has value in decreasing the incidence of infection and ameliorating the severity of the common cold.

“The solution to the puzzle is a simple one. Ascorbic acid has only rather small value in providing protection against the common cold when it is taken in small amounts, but it has great value when it is taken in large amounts.”

Vitamin C: 50 Years Later:

We are bewildered that modern medicine has tried diligently to debunk Dr. Pauling’s approach. Health care professionals have seemed perfectly fine recommending cold remedies that contain the decongestant phenylephrine (PE) for a stuffy nose. Yet anyone who bothered to look could have discovered decades ago that PE does not work as an oral formulation. The FDA is at long last proposing to eliminate it from hundreds of cold and allergy remedies. Why hasn’t there been more indignation from the medical profession about this?

What About Fever Reducers?

Health professionals who have tried hard to discredit vitamin C have embraced the idea of reducing a fever with drugs like acetaminophen, ibuprofen, naproxen or aspirin (all antipyretics) when someone has a cold or the flu. Canadian researchers challenge that idea (Proceedings. Biological Sciences, Jan. 22, 2014):

“Fever is commonly attenuated with antipyretic medication as a means to treat unpleasant symptoms of infectious diseases. We highlight a potentially important negative effect of fever suppression that becomes evident at the population level: reducing fever may increase transmission of associated infections. A higher transmission rate implies that a larger proportion of the population will be infected, so widespread antipyretic drug use is likely to lead to more illness and death than would be expected in a population that was not exposed to antipyretic pharmacotherapies.

Despite negativity from health care authorities about ascorbic acid, consumers have persisted in using vitamin C to prevent or treat cold symptoms. Perhaps that is because people taking vitamin C appear to be less likely to have to stay home sick than those on placebo (Frontiers in Immunology, April 1, 2021).

The authors note that:

“…in five trials with 598 physically active participants vitamin C decreased common cold risk by 52%.”

That’s way better than any drugstore remedy.

A meta-analysis of studies found that vitamin C significantly reduces the duration of severe symptoms, with very little impact on the duration of mild symptoms (BMC Public Health, Dec. 11,2023).

One of the problems with most studies of vitamin C or any other treatment for colds is that researchers lump all upper respiratory tract infections together regardless of the underlying virus. Although you can now determine if you have COVID-19 or influenza based on a home test, you will have no idea which of the hundreds of other viruses could be causing your symptoms.

A surprising number of supplements can help the body resist infection. Vitamin C is controversial, but a review concludes that “…cold symptoms have been shown to be less severe and resolve more quickly with oral vitamin C with a dose-dependent effect” (Nutrients, Dec. 7, 2020).

C is for Controversy!

It’s hard to understand why health professionals have reacted with hostility to something as simple and essential as ascorbic acid. Yet most doctors and medical researchers bristled when Dr. Pauling suggested that vitamin C could do more than protect us from scurvy.

To this day, many physicians reject the idea that vitamin C can be helpful. One group of researchers who were highly critical of the vitamin C hypothesis set out to prove it wrong. However, they had to eat crow and accept the results of their own study. Dr. T. W. Anderson and others, writing in the Canadian Medical Association Journal, discovered, much to their surprise, that subjects taking a 1000 mg of vitamin C every day (increasing that dose to 4,000 mg at the onset of a cold) suffered 30 percent fewer sick days.

A Reader’s Experience:

Q. I take 1000 mg of vitamin C daily with my morning orange juice. I have not had a cold or flu in more than eight years.

Before I started this regimen, I usually had at least one bout of cold or flu every year. That’s a consequence of living in South Florida with its annual tourist visits.

A. Vitamin C to reduce infection with colds or influenza has been controversial for decades. A review of the available research concluded that vitamin C supplements don’t prevent colds (Cochrane Database of Systematic Reviews, Jan. 31. 2013). However, people who took vitamin C preventively had shorter colds. Moreover, individuals doing extreme exercise in very cold climates got significant protection if they took vitamin C.

There is evidence that vitamin C can boost the activity of immune system cells (Nutrients, Nov. 3, 2017).  People who catch a cold may benefit from additional supplements of vitamin C (BioMed Research International, July 5, 2018).

Rejecting Vitamin C for the Common Cold:

Despite a good bit of research supporting the use of vitamin C during cold season, some clinicians emphasize the negative.

A review in the journal Medwave (Aug. 6, 2018) concluded:

“We identified eight systematic reviews including 45 studies overall, of which 31 were randomized trials. We concluded the consumption of vitamin C does not prevent the incidence of common cold.”

You can almost hear the self righteous delight in such a negative outcome. But we have a question for all the naysayers.

Why Doesn’t Vitamin C Work Every Time?

It is estimated that there are more than 200 distinct viruses that cause the common cold. To assume that they all react the same way to ascorbic acid would be simplistic. As far as we know, no researchers have ever attempted to identify the specific viruses that might or might not respond to vitamin C.

Imagine someone rejecting penicillin on the grounds that it did not cure every infection. That would be ridiculous, of course. Why not treat vitamin C fairly and do sophisticated research to test our hypothesis that some viruses may be more sensitive to ascorbic acid than others? Perhaps one person’s immune system is more responsive to this compound than another person’s.

Vitamin D for Prevention:

Vitamin D is also useful against respiratory infections. A meta-analysis has found that people who take this vitamin regularly are less susceptible to such problems (Health Technology Assessment, Jan. 2019). Researchers recently recommended that patients with COVID-19 take vitamin D supplements (RMD Open, Dec. 2020).

Other Supplements for Cold Relief:

The minerals zinc and selenium have well-established antiviral activity (BMJ Nutrition, Prevention, and Health, May 20, 2020). There is a substantial amount of research demonstrating zinc’s effectiveness against some cold symptoms.

A study published in the journal Antioxidants (Sept. 21, 2022) examined the way this mineral fights viruses.  It is an immune modulator, anti-inflammatory agent and antioxidant. The authors note that zinc can reduce both the duration and severity of rhinovirus infections.

You may also want to consider botanical medicines such as elderberry, astragalus and Andrographis. All of these have been shown to be helpful for treating coughs and other cold symptoms, in addition to vitamin C.

Learn More:

You can learn more about vitamin C, vitamin D, herbal remedies other nutraceuticals in our eGuide to Colds, Coughs & the Flu. In addition, it contains information on how to make Grandma Graedon’s medicinal (and delicious) chicken soup and how to use dark chocolate to calm a cough. It also offers simple instructions on another of our favorite cold remedies, hot ginger tea.

Even if you choose not to take a vitamin supplement, you should make an effort to consume foods that contain ascorbic acid. Certain foods are rich in this nutrient, including red and green bell peppers, citrus fruit and juice, kiwifruit, peaches and others.

Grandmothers around the world have relied upon chicken soup as a staple against cold symptoms. In China and elsewhere in Asia, they may add Astragalus root to the soup to boost immunity. In Europe they might add thyme to help control coughs.

To learn more about vitamin D, vitamin C, Andrographis, echinacea and other natural approaches to ease cold symptoms, you may find our eGuide to Colds, Coughs & the Flu helpful. This online resource is located under the Health eGuides tab. You will also learn about “golden milk,” which is an ancient Ayurvedic remedy popular in southeast Asia involving the spice turmeric.

Share your own vitamin C story below in the comment section. If you think this article is worth sharing, please pass it along to family and friends. Thank you for supporting our work.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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Citations
  • Holford P et al, "Vitamin C—An adjunctive therapy for respiratory infection, sepsis and COVID-19." Nutrients, Dec. 7, 2020. https://doi.org/10.3390/nu12123760
  • Martineau AR et al, "Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis." Health Technology Assessment, Jan. 2019. DOI: 10.3310/hta23020
  • Cutolo M et al, "Evidences for a protective role of vitamin D in COVID-19." RMD Open, Dec. 2020. DOI: 10.1136/rmdopen-2020-001454
  • Calder PC, "Nutrition, immunity and COVID-19." BMJ Nutrition, Prevention, and Health, May 20, 2020. DOI: 10.1136/bmjnph-2020-000085
  • Anderson TW et al, "Vitamin C and the common cold: a double-blind trial." Canadian Medical Association Journal, Sep. 23, 1972.
  • Hemilä H & Chalker E, "Vitamin C for preventing and treating the common cold." Cochrane Database of Systematic Reviews, Jan. 31, 2013. DOI: 10.1002/14651858.CD000980.pub4
  • Carr AC & Maggini S, "Vitamin C and immune function." Nutrients, Nov. 3, 2017. DOI: 10.3390/nu9111211
  • Ran L et al, "Extra dose of vitamin C based on a daily supplementation shortens the common cold: A meta-analysis of 9 randomized controlled trials." BioMed Research International, July 5, 2018. DOI: 10.1155/2018/1837634
  • Gómez E et al, "Does vitamin C prevent the common cold?" Medwave, Aug. 6, 2018. DOI: 10.5867/medwave.2018.04.7236
  • Earn, D.J.D., et al, "Population-level effects of suppressing fever," Proceedings. Biological Sciences, Jan. 22, 2014, doi: 10.1098/rspb.2013.2570
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