How To Help Prevent Viral Respiratory Infections
By Eric Madrid MD
In this article:
The “common cold” is the most common infection one can contract. There are over 220 viral strains that can cause cold symptoms. Rhinovirus is the most frequent, responsible for 50% of infections. The coronavirus is a close second, causing 15 to 30% of all colds according to a 2012 study in the Journal of Virology.
Both SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East respiratory syndrome) are virulent strains of the coronavirus. The COVID-19 virus is feared to be just as infectious and dangerous.
Common cold symptoms include cough, runny nose, fever, sore throat, shortness of breath and fatigue. The COVID-19 strain can lead to pneumonia, respiratory failure, and even death. Antibiotics kill bacteria, not viruses, so prevention of infection and symptomatic care when afflicted is crucial.
Thousands of people have been infected worldwide with the COVID-19 strain. Over a hundred more have died. International travel via planes and trains makes passing on of the virus frightful.
- Frequent handwashing with anti-microbial soap and warm water
- If you have a cough, cough into your sleeve, not your hand
- Use your knuckles instead of fingertips to push open doors or press elevator buttons
- Wear a facemask when using public transportation
- Remain well hydrated
- Consume a diet high in antioxidant containing foods (Fruits, vegetables)
- Minimize the intake of sugar and processed foods
The following supplements may also be beneficial in preventing viral infections and fighting cold symptoms. Note: We make no claim about preventing the COVID-19 virus specifically, only viral infections in general.
In my Southern California Practice, 80 percent of patients are vitamin D deficient. The incidence is higher in less sunny climates. I routinely recommend my patients supplement with vitamin D.
A 2019 study in the International Journal of Environmental Research and Public Health concluded that those with higher blood levels of vitamin D were at lower risk for Upper Respiratory Infections compared to those with lower vitamin D blood levels.
In a 2017 study in the British Medical Journal, researchers evaluated 25 randomized controlled trials which included 11,321 participants, whose ages ranged from babies to 95 years of age.
In total, vitamin D supplementation reduced the risk of an upper respiratory infection by 12 percent. Those who had vitamin D blood levels less than 25 nmol/L (10 ng/dl) noticed the biggest benefit and saw a 70% decrease in infection rate when they were supplemented. In patients who had a vitamin D level greater than 25 nmol/L (10 ng/dl), a 25% reduction in respiratory infections was seen.
Suggested dose: 1,000-2,000 IU for children and 2,000 to 5,000 IU daily for adults.
As we age, the absorption of important minerals like zinc can be impaired. The WHO or World Health Organization estimates that up to one-third of the world population is deficient in Zinc. Additionally, poor dietary intake of zinc-containing foods or routine ingestion of alcohol can also result in chronically low zinc levels. Zinc deficiency is associated with increased risk for infection, along with other issues.
A 2016 study in the British Journal of Clinical Pharmacology concluded, “common cold patients may be encouraged to try zinc lozenges for treating their colds” while a 2017 study concluded, “common cold patients may be instructed to try zinc lozenges within 24 hours of the onset of symptoms.”
Another 2017 study showed both zinc gluconate lozenges and zinc acetate lozenges are equally effective.
Lastly, a 2018 study in the Journal of Immunology Research showed that a zinc deficiency could weaken the immune system and that zinc-dependent proteins are required to achieve an optimal immune response against invading pathogens.
Suggested dose: zinc lozenges, 30 mg as directed on the label. Also available in capsules and multivitamins.
Note: Although Elderberry appears helpful in preventing influenza, some evidence suggests it should NOT be taken to prevent or treat COVID-19.
Elderberry (Sambucus sp.), a flowering plant, has been used for hundreds of years for medicinal purposes by native populations all over the world. In recent years, elderberry’s popularity has caught on. Indigenous Americans are said to have used elderberries as treatment for various infections and fever.
A 2016 study showed that elderberry could reduce the duration of cold symptoms in airline travelers.
A 2019 study in Complementary Therapies in Medicine evaluated 180 participants.
They found that Elderberry could substantially reduce upper respiratory infection symptoms. They concluded that “These findings present an alternative to antibiotic misuse for upper respiratory symptoms due to viral infections, and a potentially safer alternative to prescription drugs for routine cases of the common cold and influenza
Lastly, a 2001 study and 2002 study both showed elderberry’s benefit in strengthening the immune system response. This is key to preventing and fighting off any infection. In addition, a 2012 study concluded the concentrated juice of elderberry had a beneficial effect by stimulating the immune system’s response and thereby preventing a viral infection.
Elderberry is available as a supplement, syrup, gummy and lozenge.
- A Human Coronavirus Responsible for the Common Cold Massively Kills Dendritic Cells but Not Monocytes, Journal of Virology Jun 2012, 86 (14) 7577 7587; DOI: 10.1128/JVI.00269-12
- Pham H, Rahman A, Majidi A, Waterhouse M, Neale RE. Acute Respiratory Tract Infection and 25-Hydroxyvitamin D Concentration: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health. 2019;16(17):3020. Published 2019 Aug 21. doi:10.3390/ijerph16173020
- Martineau Adrian R, Jolliffe David A, Hooper Richard L, Greenberg Lauren, Aloia John F, Bergman Peter et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data BMJ 2017; 356 :i6583
- Hemilä, H., Petrus, E. J., Fitzgerald, J. T., and Prasad, A. (2016) Zinc acetate lozenges for treating the common cold: an individual patient data meta-analysis. Br J Clin Pharmacol, 82: 1393–1398. doi: 10.1111/bcp.13057.
- Hemilä H, Fitzgerald JT, Petrus EJ, Prasad A. Zinc Acetate Lozenges May Improve the Recovery Rate of Common Cold Patients: An Individual Patient Data Meta-Analysis. Open Forum Infectious Diseases. 2017;4(2):ofx059. doi:10.1093/ofid/ofx059.
- J Immunol Res. 2018 Oct 17;2018:4315140. doi: 10.1155/2018/4315140. eCollection 2018.
- Nutrients. 2016 Mar 24;8(4):182. doi: 10.3390/nu8040182.
- Eur Cytokine Netw. 2001 Apr-Jun;12(2):290-6.
- Isr Med Assoc J. 2002 Nov;4(11 Suppl):919-22.
- Biosci Biotechnol Biochem. 2012;76(9):1633-8. Epub 2012 Sep 7.