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

Why does the medical establishment have such antipathy to ascorbic acid against the common cold? You would think vitamin C was worthless. It is essential!

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. 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.

Suffering a Cold in the Time of COVID:

Although precautions many of us have taken against COVID-19 have greatly reduced the spread of influenza, some people are still suffering with colds this year. One reader wondered whether supplements could enhance the immune system.

Q. A few days ago, I got the sniffles and a sore throat. Then I developed a cough. Needless to say, I freaked out thinking I might have caught COVID. Luckily the test was negative.

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:

A. A surprising number of supplements can help the body resist infection. Vitamin C is controversial, but a recent 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).

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). 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.

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. Taking vitamin C once you start to experience cold symptoms doesn’t seem to be very effective.

A recent 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.

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. To learn more about this and other vitamins and minerals, we highly recommend the book, Fortify Your Life: Your Guide to Vitamins, Minerals, and More by Dr. Tieraona Low Dog. A special paperback edition is only available at this link.

Share your own vitamin C story below in the comment section.

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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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  • 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
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