How to Avoid and Treat the Common Cold

Randy Rasico
March 22, 2020

According to the CDC, millions of people in the United States get the common cold every year. Each adult, on average, receives 2-3 colds per year and most recover in 7-10 days. There are many treatments out there, but have you ever wondered which ones actually work, or even, how well they work? I’ve wondered myself what the science has to say and so I did some digging to find out. If I wanted to explain to someone that a supplement worked for me, would they be convinced enough to use it? Or would they just suffer more in being sick? After all, one might need to be fairly convinced that something works before spending their hard-earned money to justify its cost. This article addresses vitamin C, vitamin D, elderberry, zinc, cayenne, and other suggestions. Some of the treatment suggestions are made inferring from the scientific studies addressed. This includes important things such as what to use, dosages, and timing. An improper dose or timing of a supplement may mean the difference between “it works for me!” and “it didn’t really seem to do much.” Here is what the research says.

Note: This paper is not intended for treating COVID-19, however, I do not doubt that some of these treatments may be quite helpful. The common cold is a term that refers to many types of respiratory viruses. Influenza (though not a cold) is also a respiratory virus, and the United States has a few different ones that are new every year. All of these are respiratory viruses and the research noted below shows what we know to be effective against them and different ways we can aid our immune systems to fight these viruses. COVID-19 is also a respiratory virus and our immune systems are used to fight against it. Therefore, I do not doubt that these treatments will also have some kind of efficacy against COVID-19. If you are short on time, just skip to the end and begin reading at “Other Suggestions.”

Vitamin C

Taking 1-3g of vitamin C daily for the common cold has not been proven to do anything, according to one study.1 This might be because vitamin C is a water-soluble vitamin, meaning that the body uses only a given amount of the vitamin at one time and then excretes the rest through the urine. Because of this, vitamin C must be taken continually throughout the day to be most effective. There may also be other factors about how the body processes vitamin C that scientists may not know. For example, it puzzles them how 1,000mg a day of vitamin C can significantly lower blood lead concentration compared to 200mg a day of vitamin C which does nothing significant, even though in both groups, vitamin C blood concentrations were not different from each other.2 Therefore, just because taking a lower dose of vitamin C has the same measured level in the blood as a higher dose, that doesn’t mean that they both have equal effects.

Some research has noted the effectiveness of vitamin C in reducing cold and flu symptoms. In one study, involving 463 students, those in the control group who were sick were treated with pain relievers and decongestants. Those in the test group who weren’t sick yet were administered with 1,000mg vitamin C doses 3 times daily, while those in the test group who reported symptoms of sickness, were treated with hourly doses of 1,000mg of vitamin C for the first 6 hours and then 3 times daily thereafter. The study found that those who supplemented with vitamin C experienced an 85% decrease in cold and flu symptoms.3 If the result of this study is valid, then it may be very effective to take vitamin C before any symptoms appear and then continue to take it in increasing doses once symptoms do appear.

However, in a meta-analysis of vitamin C, this study was excluded because there was no placebo group.4 (pg. 32). However, one could argue that “pain relievers and decongestants,” are similar to a placebo, since they are medications taken to make one feel well. However, one of those two medications could also have directly or indirectly made the cold worse, thus skewing the outcome. Nonetheless, if the lack of a placebo alone in this trial was responsible for an 85% decrease in cold and flu symptoms, is there really any harm popping down sugar pills (i.e. placebos) to obtain such a high benefit?

Though this study was excluded, six studies included in this meta-analysis, however, did conclude that for participants under heavy physical and/or cold stress (i.e. marathon runners, skiers, and soldiers), 250-1,000mg of vitamin C daily halved their chances of getting a cold (pg. 14). In addition, thirty other trial comparisons observed an 8% (3% to 13% range) reduction in cold duration for adults and a 13.5% (5% to 21%) reduction in children who took 1,000-2,000mg of vitamin C daily. Therefore, vitamin C supplementation is at the very least 8% effective on average. However, considering that both children and adults received this same dose range, though their body weights are different, adults might see an even greater benefit at higher doses.

Most studies available used doses under 3g of vitamin C (which is considered a high dose according to the meta-analysis). However, there were a lack of studies that used doses of 8g or more, therefore necessitating the need for more research. Thus, mega-doses of vitamin C could be very effective but we don’t have enough science to prove it yet.

What I would like to see and what is lacking in the existing research of vitamin C are studies that use mega doses of 1g or more at the very onset of symptoms and continual doses at various intervals of the day using L-ascorbic acid (the natural form of vitamin C) or using ascorbic acid blended with various flavonoids to total 8-12g a day.

One thing to consider is that since Vitamin C and bioflavonoids both occur together in nature, perhaps they have a synergistic effect. Combining the two, along with other naturally occurring co-factors, may help one to see the most benefit. In other words, Vitamin C from real foods might be better. Anthocyanins, a flavonoid compound found in fruits, was shown to have strong anti-inflammatory, antiviral, and immune boosting effects. Some of the best sources are strawberries, cranberries, blueberries, and blackberries.5 This is another great reason why we should be including fruits in our diet.

A meta-analysis on the use of flavonoid supplementation in the dose range of 200-1,200mg found that flavonoids decreased upper respiratory tract infection occurrences by 33% and decreased sick day count by 40% with supplementation.6 That means a ten day cold would only last six days. In the meta-analysis discussed earlier in the supplementation of vitamin C (ref. 4), they only found an 8-14% reduction in the length of a cold. Comparing the two, this means that the bioflavonoids found in whole foods are far superior than the typical over-the-counter vitamin C that gets made in a lab. Specifically, at least 26-32% more superior when considering its effect on the immune system alone.

Based on the findings of these studies, here are some recommendations. When looking at the ingredients list of a vitamin C product, check for things like rose hips, acerola cherry, and other bioflavonoids. These ingredients help make vitamin C more bioavailable (i.e. more effective). Test out vitamin C in smaller doses before raising it to see how much your body can tolerate or how well the particular brand works with your body. For some people and with some types of vitamin C, high doses can upset the stomach. If you have a history of kidney stones, then don’t take high doses of vitamin C. Personally, I have taken large doses of Viva Naturals Vitamin C without any ill effects. Raw Whole Food Vitamin C from Smarter Vitamins also seems like a good product. If your vitamin C is coming from whole foods, you may not need as high a dose.

Vitamin D

Many Americans are deficient in vitamin D. If the body can synthesize 10,000 to 20,000 IU of Vitamin D per hour in the sun (167-333 IU per minute), why is the recommended intake currently at such a low dose of 600 IU per day? That’s essentially saying that 2-4 minutes of sun per day is enough. If most Americans spend most of their time indoors at home, work, or in their vehicles, and the only time they spend outside is walking to and from their cars, then they may not even get that small amount. What further becomes a problem is that there are few dietary sources of Vitamin D and even those sources have quite minimal amounts. The only other way to naturally get Vitamin D is through sun exposure. However, in the winter, it can be cold out and so we wear too much clothing. In the summer, it’s too hot and so we stay indoors. Or, when we do go out, we wear sunscreen, which prevents Vitamin D from being synthesized. Historically speaking, it’s not natural to stay indoors all the time. Air-conditioning wasn’t a thing. Walking or horseback was the mode of transportation, and our ancestors didn’t have sunscreen.

The amount of vitamin D that is commonly recommended may not be enough for optimal health. The Recommended Daily Allowance (RDA) of vitamin D was placed at 600 IU per day by the Institute of Medicine in 2011. However, what many people may not know is that this value was issued for maintaining bone health and normal calcium metabolism. Other aspects of health were not considered, such as immune function, cancer, and disease prevention. Doctors and other health experts may think that you’re fine as long as your Vitamin D blood levels are above 20 ng/ml. However, just because your bones are fine, that doesn’t mean that the rest of your body is fine or even in optimal health for that matter. To prevent immediate disease or dysfunction in the body like Rickets by maintaining the RDA, does not mean that you are improving or optimizing your health. Neither does it necessarily mean that you are preventing other diseases and dysfunction down the road.

However, even with this low level of 20 ng/ml being considered adequate, more than 40% of American adults are vitamin D deficient.7 Those with darker skin pigmentation were even more deficient (82.1% in blacks, 69.2% in Hispanics). While darker skin pigment helps against sunburns and against an over synthesis in vitamin D for those who live in hot climates and spend a lot of time outside, it is not advantageous for quickly synthesizing vitamin D through the sun. A person with darker skin may need 5 to 10 times more sun exposure to get the same amount of vitamin D as people with lighter skin could get in only 10 to 15 minutes.8

This deficiency of vitamin D is alarming when we consider its effects on immune health. In one study, patients susceptible to respiratory tract infections (RTIs) for more than 42 days in the previous year were placed in a test group to receive 4,000 IU of vitamin D3 daily for a year. The test group had 42% incidents of one or more infections a year, while the control group had 63% incidents of infection. Thus, the test group had 21% less incidents of infection. In other words, people in the vitamin D group had a 21% increased chance of not getting sick at all.

An important fact in this study was that for the first four months of supplementation, there was no difference between the two groups in RTIs, but after that time, the vitamin D group clearly had a better outcome. For us, this could mean that supplementing with vitamin D only when we feel like we’re getting sick but not supplementing the rest of the year or receiving a good amount of vitamin D some other way, will probably not be enough to help immunity. Also, if the number of RTIs were to be counted after the initial 120 days, then we might expect a much lower percentage of RTIs in the test group. Meaning, vitamin D may very well help immunity more than this study shows.

Ninety-five percent of the patients’ vitamin D level before the study were at a median of 16 ng/ml. Only 11% had levels above 30 ng/ml and 4% had levels above 40 ng/ml. Therefore, most patients were deficient in vitamin D. In the study, the total number of RTIs in the control group at the end of the study were 120 versus 86 in the vitamin D group. This means that those who supplemented with vitamin D had 28% (86/120 = .72 - 1 = -0.28) fewer infections.9

UVB rays from the sun help our bodies synthesize vitamin D. Midday is the best time to get them. The farther north you live, the more difficult it will be to synthesize vitamin D from the sun.

As far as supplements go, I’ve read and heard that liquid vitamin D is the most bioavailable and D3 is better than D2. You could also have your vitamin D levels checked before and after a course of supplementation to see if the supplements are working. However, vitamins A, D, and K work synergistically, and so not having them together in supplementation or in one’s diet could be harmful when supplementing with vitamin D. The optimal or healthy vitamin D level is debatable in the science community, but 35-60 ng/ml is probably optimal.

Elderberry

Elderberry contains flavonoids (antioxidants), and vitamin C.

In one study, sixty patients who had influenza-like symptoms for 48 hours or less were given 15ml of elderberry syrup four times a day for five days. Symptoms were relieved four days earlier than in the placebo group.10 Granted, the common cold and the flu are not the same. However, they are both upper respiratory tract viruses and share many similarities.

In another study, those who took elderberry supplements had significant reductions in cold duration and severity.11 Thus, elderberry helps the common cold as well.

Elderberry flavonoids were shown to inhibit H1N1 virus in vitro by blocking host cell entry and/or recognition.12 The study concluded that the effects were comparable to prescription medications like Amantadine and Oseltamivir (Tamiflu). Elderberry also works by strengthening a person’s immune response to a virus and inhibiting the virus’ entry and replication. It was surprisingly even more effective at blocking the viral cycle at later stages of the virus which means that it has a greater chance in overcoming the virus.13 Elderberry also increased the number of cytokins in the body, which are chemical messengers that help the immune system be more efficient. A 2019 meta-analysis concluded that “supplementation with elderberry was found to substantially reduce upper respiratory symptoms.”14 According to the research, elderberry seems to be a really good option for treating the cold and flu. However, the timing and dosage of this supplement may be very important to see similar results as they are found in the studies.

Zinc

A meta-analysis of zinc lozenges for the common cold concluded that zinc reduces cold duration an average of 33 percent.15

The Institute of Medicine establishes the tolerable upper intake level at no more than 40mg of zinc per day for adults, 34mg for ages 14-18, and 23mg for ages 9-13 to avoid zinc toxicity. Too much zinc can lower immunity and cause other significant problems. Do not take zinc with antibiotics or penicillamine.

There are zinc lozenges out there that also have elderberry and vitamin C in them. One of the benefits of lozenges for treating respiratory infections is that the back of your throat is part of your respiratory system and also part of what is infected during a cold. Therefore, one might see better benefits with a product that continually coats or passes through the throat so that there is a direct topical application to the viral infection.

Cayenne Pepper

Cayenne pepper thins mucus in the nasal passageways and sinuses like decongestants and expectorants (e.g. Guaifenesin). This helps to prevent nasty chest congestion that may need to be treated later with antibiotics. Cayenne helps to reduce nasal congestion by clearing up the nasal passageways, effectively draining the sinuses. In my own anecdotal experience, I affirm this to be true. At the first sign of a cold when my throat feels to be the slightest bit unusual, I take a half to one teaspoon of this cayenne tincture that I have and pour it into a 6-8oz glass of water and then continually sip on it. Being busy, I don’t always do it right away. However, if I have a sore or scratchy throat and have been coughing a bit, it feels like the spiciness of the cayenne just burns all of that away and then my throat feels at 90-100%. There was one night I was sick and couldn’t get to sleep. I was desperate. I took some cayenne. It significantly reduced my chest-related cough and I was able to sleep (surprisingly). In my personal experience, cayenne significantly reduces cold severity and length.

I hypothesize that these may be some of the reasons why cayenne is so effective: Cayenne increases blood circulation to the sinuses, thereby allowing more white blood cells to effectively get everywhere that they need to go. The spiciness of cayenne in contact with the throat sends signals to the immune system that you are under attack and need immediate reinforcements, thereby sending T-cells and antibodies into overdrive to combat that area. Cayenne is also high in vitamin C, which can be helpful in fighting a cold.

Other suggestions:

Use soap and hot water to wash your hands rigorously, applying a decent amount of friction. Hand-sanitizer is good. However, it doesn’t always kill everything. Washing hands is always better if done right. Avoid touching your mouth, eyes, and face. For the sake of others, contain your sneezes by sneezing into your shoulder or elbow so that tiny virus-water droplets don’t spread across the entire room or store. Avoid sugar, as it suppresses the immune system. Avoid any kind of nutritional deficiency. Get plenty of rest. Avoid stress or find ways to de-stress since stress significantly reduces immune function. Maintain a healthy gut microbiome by eating a balanced diet and be sure to include fruits, vegetables, and probiotics, since 80% of your immune system resides in the gut. Drink plenty of water to help your body flush out all the bad stuff, and to help lubricate the respiratory tract, enabling your body to eliminate the virus more effectively. Don’t always turn immediately to fever-reducers like ibuprofen when you have a fever. A fever is your body’s natural immune response to kill off that virus. Take fever-reducers when your fever gets too high or use other natural means to reduce the fever. How “high” would that be? Ask your doctor or do some research to make a judgement call on that. If the fever or chills become too miserable or out of control, or you can’t sleep, then taking ibuprofen would be good. When the time comes, you’ll probably “just know” when to take it.

Other supplements and treatments to try or look into: Garlic, N-Acetyl-Cysteine (NAC), echinacea, goldenseal, licorice, ginger, St. John’s wort, astragalus, Lomatium, olive leaf extract, essential oil blends (e.g. clove, rosemary, Eucalyptus, cinnamon, lemon), saunas, hot tubs, laying in the sun (for increased temperature and sweating), chicken and vegetable broth, walking/exercise, prayer, a positive mood/laughter/avoiding negativity, avoiding dairy, and avoiding junk foods or anything that is highly processed.

Conclusion:

Earliest treatments and preventative care are most effective for the common cold. Maintaining optimal vitamin D levels throughout the year is necessary to support the immune system. Forty percent or more of the population is deficient in vitamin D. People who supplemented with vitamin D had 28% less infections. Small doses of vitamin C are probably ineffective but 250-1,000mg of vitamin C daily can reduce your chance of getting sick by 50% if you are under heavy stress. Mega-doses of vitamin C are debatable. However, one study showed that mega-doses of vitamin C could reduce cold and flu symptoms by 85 percent. More scientific research is needed in the use of mega-doses, however, to determine its efficacy. Studies have shown that flavonoids can decrease the chance of getting sick by 33% and decrease the number of sick days by 40 percent. Therefore, it’s a good idea to eat plenty of berries. A study showed that people who took an Elderberry supplement had four less sick days with the flu than those who didn’t. A 2019 meta-analysis concluded that Elderberry significantly reduced upper respiratory symptoms. Another study said that the beneficial effects of Elderberry were comparable to Tamiflu. A meta-analysis of zinc lozenges for the common cold concluded that zinc reduced cold duration an average of 33 percent. Cayenne also works really well in treating a sore throat and significantly lessens the severity and length of the common cold (in my personal experience). Real foods are likely more effective at treating the common cold than synthetically-made vitamins since they contain other bioactive compounds.

Plan of Action:

Maintain proper vitamin D levels for optimal health and maintain a healthy gut microbiome throughout the year. At the very first signs of a cold when you notice your nose and/or throat feel unusual, do not hesitate to label it as sickness—and then do the following: Sip on some form of liquid cayenne (repeat this as needed or however often you are willing to tolerate the heat). Take 1,000mg vitamin C and/or flavonoids every hour for ten hours in the day, and repeat this every day until your cold symptoms have subsided, or for 3-5 days. Alternatively, eat or juice some fruits high in vitamin C and flavonoids. Another alternative if the high dose is a concern and you don’t have time for eating a bunch of fruits: Take a vitamin C supplement that is derived from only whole foods. Even though the dose is lower, it could have an even more profound effect because of all the bioflavonoids. Remember, it was the specific flavonoids in elderberry that had such a profound effect on the H1N1 virus. Finally, suck on some zinc/elderberry/vitamin C lozenges every hour.

I believe that these steps will significantly help, even if not all of them are taken. Depending on the person and the virus, one or two of them could be adequately sufficient. Try different things and see what works for you.

If chest congestion symptoms develop and persist, sustained-release guaifenesin tablets work well to help the body get rid of that (be sure to cough out that phlegm). I would avoid using cough suppressants for chest congestion because coughing is necessary to get phlegm out of there. Chest congestion can turn into pneumonia—and people can die from that. So, coughing can be good for you. If your throat is bothering you, gargle with saltwater, get some honey and coconut oil together in a spoon and swallow (Manuka honey, if you have money to burn), or sip on an herbal tea mixed with some lemon juice and raw wild honey. If none of that works, continually sipping and swallowing small ice pieces will help alleviate the pain.

Medical disclaimer: Not intended to treat, diagnose, or cure any disease or ailment. Please read and fully understand potential adverse effects before using any product or treatment method. These statements have not been reviewed by a medical professional or organization and are for informational and educational purposes only. This author assumes no responsibility for action taken that results in any illness or injury. Please consult your doctor before using any supplements or treatment.

References

Vitamin C

1. Audera, C., Patulny, R. V., Sander, B. H., & Douglas, R. M. (2001, October 1). Mega‐dose vitamin C in treatment of the common cold: a randomised controlled trial. Retrieved February 16, 2020, from Wiley (MJA) https://onlinelibrary.wiley.com/doi/abs/10.5694/j.1326-5377.2001.tb143618.x

2. Vitamin C. (2020, January 14). Retrieved February 16, 2020, from Linus Pauling Institute https://lpi.oregonstate.edu/mic/vitamins/vitamin-C

3. Gorton, H. C., & Jarvis, K. (2005, November 4). The effectiveness of vitamin C in preventing and relieving the symptoms of virus-induced respiratory infections. Retrieved February 16, 2020, from Science Direct https://www.sciencedirect.com/science/article/pii/S0161475499700059

4. Douglas RM, Hemilä H, Chalker E, D’Souza RRD, Treacy B (2004, October 18). Vitamin C for preventing and treating the common cold (Review). Retrieved February 16, 2020, from Wiley, The Cochrane Library https://helda.helsinki.fi//bitstream/handle/10138/228061/Douglas_et_al_2004_The_Cochrane_Library_Colds.pdf?sequence=1

5. Jones, Taylor (2016, June 17). The 15 Best Foods to Eat When You’re Sick. Retrieved February 16, 2020, from Healthline Nutrition https://www.healthline.com/nutrition/15-best-foods-when-sick#section12

6. Somerville, V. S., Braakhuis, A. J., & Hopkins, W. G. (2016, May 16). Effect of Flavonoids on Upper Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-Analysis. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pubmed/27184276

Vitamin D

7. Forrest, K. Y. Z., & Stuhldreher, W. L. (2011, January). Prevalence and correlates of vitamin D deficiency in US adults. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pubmed/21310306

8. Barrymore, John (2009, August 20). How does the sun affect people with dark complexions? Retrieved February 16, 2020 from HowStuffWorks https://health.howstuffworks.com/skin-care/beauty/sun-care/sun-affect-dark-complexions.htm

9. Bergman, P., Norlin, A.-C., Hansen, S., & Björkhem-Bergman, L. (2015, August 30). Vitamin D supplementation to patients with frequent respiratory tract infections: a post hoc analysis of a randomized and placebo-controlled trial. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553208/

Further reading:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447082/
https://www.healthline.com/nutrition/vitamin-d-deficiency-symptoms#section1
https://www.healthline.com/nutrition/vitamin-d-from-sun#skin-color
https://www.hsph.harvard.edu/nutritionsource/vitamin-d/
https://articles.mercola.com/sites/articles/archive/2009/03/21/Can-Vitamin-D-Cure-the-Common-Cold.aspx
https://chriskresser.com/vitamin-d-more-is-not-better/

Elderberry

10. Zakay-Rones, Z., Thom, E., Wollan, T., & Wadstein, J. (2004, April). Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pubmed/15080016

11. Tiralongo, E., Wee, S. S., & Lea, R. A. (2016, March 24). Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4848651/

12. Roschek, B., Fink, R. C., McMichael, M. D., Li, D., & Alberte, R. S. (2009, July). Elderberry flavonoids bind to and prevent H1N1 infection in vitro. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pubmed/19682714

13. University of Sydney. (2019, April 23). Elderberry compounds could help minimize flu symptoms, study suggests. Retrieved February 16, 2020, from ScienceDaily https://www.sciencedaily.com/releases/2019/04/190423133644.htm

14. Hawkins, J., Baker, C., Cherry, L., & Dunne, E. (2018, December 18). Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trials. Retrieved February 16, 2020, from ScienceDirect https://www.sciencedirect.com/science/article/abs/pii/S0965229918310240

Further reading:
https://articles.mercola.com/sites/articles/archive/2019/10/21/elderberry-extract-for-influenza.aspx
https://www.liebertpub.com/doi/abs/10.1089/acm.1995.1.361

Zinc

15. Hemilä, H. (2017, May 2). Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. Retrieved February 16, 2020, from PubMed https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5418896/

Further reading:
https://ods.od.nih.gov/factsheets/Zinc-Consumer/
https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/
https://www.healthline.com/health-news/is-zinc-the-best-remedy-for-the-common-cold#5

Further reading for cold and flu treatments:

https://chriskresser.com/the-top-20-natural-remedies-for-cold-and-flu/

Recommended health websites for learning and investigation:

Healthline.com
Chriskresser.com
Webmd.com
Examine.com
Drugs.com
Mercola.com
Mayoclinic.org