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Vitamin D & Coronavirus Prevention: Facts & Myths

by | Dec 2, 2021 | Wellness Blog: Covid, Wellness Blog: Wellness

Ok, But What Exactly is Vitamin D?

Vitamin D is a fat-soluble vitamin that helps to absorb the minerals calcium and phosphorous. As previously mentioned, it plays a vital role in forming and maintaining strong bones, regulating normal immune system function, and limiting inflammation. But it also aids in sturdy teeth, maintaining heart and lung health, and combating depression and other diseases.

Vitamin D is a family of compounds. Vitamin D is maintained in the body thanks to two mechanisms, Vitamin D2 and Vitamin D3.

Vitamin D2

D2 is present in some foods & food supplements and ingested into the body.

Vitamin D3

D3 is primarily produced by the body at the skin level under the influence of solar radiation (the sun). It is also available as a supplement.

The two forms of Vitamin D2 and D3 have the same effect on the body and therefore it is important to know the sum of their quantities. The total concentration of Vitamin D 25-Hydroxy (D2+D3) is used to estimate the reserve of Vitamin D in the body.

Vitamin D Sources

• Sunlight: 5 to 30 minutes of sun exposure at least twice a week

• Supplements (600 to 800 international units a day), but don’t be alarmed if your doctor has you on a higher dose

• Fatty fish such as trout, salmon, tuna and mackerel

• Cheese

• Egg yolks

• Mushrooms

• Fortified foods, including cereal, milk and orange juice

Source: NIH Health Professional Fact Sheet

Then Why the Interest in Vitamin D?

The short answer is because vitamin D supplements are generally considered safe. Many patients and physicians alike are strong believers in the overall health benefits of vitamin D. Most deficiencies are discovered by a lab test, you can check your level here with an At-Home Vitamin D Test, and when it’s low it’s safe for most people to take in reasonable doses. But remember, if your supplementing, most physicians recommend periodic lab monitoring to ensure an optimal level and to rule out vitamin D toxicity.

All Right Already, So What Does the Science Say on Vitamin D and Covid?

Further research is needed to determine the role vitamin D and vitamin D deficiency might play concerning COVID-19. This is because there are numerous conflicting studies both for and against the efficacy of vitamin D to aid in the prevention and treatment of covid. For example, a recent study published on JAMA observed that Black individuals who have higher levels of vitamin D were less likely to test positive for COVID-19 than people with sufficient levels. However, conversely, a 2020 study conducted in Brazil concluded that a single high dose of vitamin D did not affect disease severity.

In the meantime, if you’re concerned about your vitamin D reserves or want to monitor your supplement dosing, you may want to have your Vitamin D levels checked. Even though the jury is still out on whether it helps with Coronavirus Prevention, having optimum vitamin D levels helps your body function at its best.

5 Reasons To Keep PCR Home COVID Test Kits on Hand. 4U Health. Updated December 6, 2021.

Ditch Nose Swabs for a Home Saliva PCR Covid Test Kit. 4U Health. Updated December 3, 2021.

About 4U Health

4U Health offers at-home lab testing to help you feel like your best self. Visit us at to learn about our COVID-19 Antibody Self-Collection At Home Test Kit, explore healthy living and wellness topics, and view our full at-home lab testing menu.

If you’re interested in a PCR at home COVID test to detect COVID-19 (including Omicron and its other variants), check out 4U Health’s COVID-19 Active Infection Self-Collection Test. It’s recommended for children 5+ and adults alike. For the timeliest results, we advise having a “just-in-case” saliva kit stocked in your medicine cabinet so you can test on your terms. Overnight shipping is included and results are typically within 24 hours of receipt by the lab.

How Do I View the National Institute of Health’s Vitamin D Fact Sheet for Consumers?

NIH VItamin D Fact Sheet for Consumers. Updated March 22, 2021. Accessed December 3, 2021.

Where Can I Find Supportive Research Information About Vitamin D as It Relates to COVID-19?

Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections. April 2, 2020. Accessed December 3, 2021.


Front Immunol. Angajala A, Lim S, Phillips JB, et al. Diverse Roles of Mitochondria in Immune Responses: Novel Insights into Immuno-Metabolism. URL. July 12, 2018. Accessed Dec 3, 2021.

Centers for Disease Control and Prevention. Information for Where You Live, Work, Learn, and Play. URL. Updated August 24, 2021. Accessed Dec 3, 2021.

Nutrients. Greiller CL, Martineau AR. Modulation of the immune response to respiratory viruses by vitamin D. URL. May 29, 2015. Accessed Dec 3, 2021.

The Journal of Clinical Endocrinology and Metabolism. Holick MF, Binkley NC, Bischoff-Ferrari HA, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline URL. June 6, 2011. Accessed December 3, 2021.

The Journal of Clinical Endocrinology and Metabolism. Kanhere M, He J, Chassaing B, et al. Bolus Weekly Vitamin D3 Supplementation Impacts Gut and Airway Microbiota in Adults with Cystic Fibrosis: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial. URL. February 1, 2018. Accessed December 05, 2021.

Los Angeles Times. Coronavirus stalks the aged and infirm, who face the most serious, lethal risk. URL.  March 3, 2020. Accessed December 5, 2021.

International Journal of Cell Biology. Reshi ML, Su YC, Hong JR. RNA Viruses: ROS-Mediated Cell Death. URL. May 8, 2014. Accessed December 5, 2021.

International Journal of Molecular Sciences. Ricca C, Aillon A, Bergandi L, Alotto D, Castagnoli C, Silvagno F. Vitamin D Receptor Is Necessary for Mitochondrial Function and Cell Health. URL. June 5, 2018. Accessed December 5, 2021.

Clinical & Translational Immunology. Shukla SD, Budden KF, Neal R, Hansbro PM. Microbiome effects on immunity, health and disease in the lung. URL. March 10, 2017. Accessed December 5, 2021.

The American Journal of Clinical Nutrition. Tripkovic L, Lambert H, Hart K, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. June 6, 2012 URL. Accessed December 5, 2021.

Infect Immun. White JH. Vitamin D signaling, infectious diseases, and regulation of innate immunity. URL. May 27, 2008. Accessed December 5, 2021.

The Lancet: Diabetes & Endocrinology. Nita GF, Vitamin D for COVID-19: a case to answer?. URL. August 3, 2020. Accessed December 5, 2021.

Mayo Clinic Proc. Kennel KA, Drake MT, Hurley DL, Vitamin D Deficiency in Adults: When to Test and How to Treat. URL. August 2010. Accessed December 5, 2021.

Updated: December 6, 2021