What to Know About Vitamin D and COVID-19 Treatment

Dr. Brett Berner
4 min readMar 14, 2021


Vitamin D Supplementation and COVID-19

Yes. The coronavirus vaccine has been approved and is currently in use. However, before then, many people were using and are still using vitamin d supplementation to optimize their immune system and help them arrest COVID-19.

Many posts on social media push supplements as protective agents against COVID-19. However, the director of the National Institute of Allergy and Infectious Diseases, Anthony Fauci, MD, cautioned against unsupervised use of these immune-boosting supplements, noting that they do “nothing” in the true sense.

Some studies have found that vitamin D deficiency can increase the severity of COVID-19.

But one supplement might be exempted — and that’s vitamin D. It is commonly referred to as the “sunshine vitamin.”

According to Fauci, vitamin deficiency increases a person’s susceptibility to infection. Note that Fauci wasn’t referring to COVID-19, but the general role of vitamin D in optimizing the immune system, especially in those who already were deficient in it.

While there may be no solid evidence to show that vitamin D treats or prevents COVID-19, results from studies conducted so far give some hope.

The Link Between Vitamin D Deficiency and COVID-19

Earlier studies suggested that vitamin D was effective against respiratory tract infections. There were variations in the benefits (among these studies), but supplementing with vitamin D seemed to be more effective in people already deficient in it.

Recent studies suggest that a vitamin D deficiency may increase a person’s risk of COVID-19 infection and the severity of the disease.

Medical researchers are investigating the therapeutic effects of vitamin D against the symptoms of COVID-19.

Some studies have found that the death rates due to COVID-19 are higher in countries farther away from the equator, where there are many vitamin D deficient people due to the low amount of sunlight.

Sunlight is a natural source of vitamin D.

Our bodies produce vitamin D when they are exposed to the sunlight, and in the winter (colder months), the rates of vitamin D deficiency can increase.

It is important to note that many factors may play a role in the high rates of COVID-19 cases in the northern latitudes. But then, a September 2020 study published in JAMA Network Open emphasized the immune-boosting effect of COVID-19.

According to the study, people deficient in Vitamin D had a higher chance of testing positive for COVID-19. Moreover, this trend persisted even when they controlled other risk factors — like obesity, age, etc. that might complicate COVID-19.

Results from studies conducted so far suggest that vitamin D supplements might be helpful in COVID-19 treatment.

Another study by Nogués et al. has found that treatment with calcifediol reduced ICU admission and mortality in COVID-19 patients. Out of the 930 participants involved in the study, 551 were randomly assigned to calcifediol treatment, while 379 were given as controls. Overall mortality was 10%. In the Intention-to-treat analysis, 36 (6.5%) out of 551 patients treated with calcifediol at admission died compared to 57 patients (15%) out of 379 controls.

These studies show that vitamin D deficiency in COVID-19 patients constitutes a risk for poor prognosis.

Should You Take Vitamin D?

Well, even before the conclusion of these studies, it wouldn’t be out of place to consider supplementing with vitamin D.

It is important to note that most Americans are already deficient in vitamin D and could benefit from vitamin D supplementation, even if not for COVID-related reasons.

According to a study, at least 41% of American adults are deficient in vitamin D. The risk seems to be greater in people with dark skin — with 82% of Blacks and 63% of Hispanics having low vitamin D levels, respectively.

Other factors such as obesity, limited exposure to the sun, and some underlying medical conditions increase the risk of deficiency.

Getting adequate vitamin D from foods may be difficult, so supplementing is recommended. However, you must consult your healthcare provider first.

Disclaimer: Dr. Berner does not diagnose, treat, or prevent any medical diseases or conditions; instead, he analyzes and corrects the structure of his patients with Foundational Correction to improve their overall quality of life. He works with their physicians, who regulate their medications. This blog post is not designed to provide medical advice, professional diagnosis, opinion, treatment, or services to you or any other individual. The information provided in this post or through linkages to other sites is not a substitute for medical or professional care. You should not use the information in place of a visit, consultation, or the advice of your physician or another healthcare provider. Foundation Chiropractic and Dr. Brett Berner are not liable or responsible for any advice, the course of treatment, diagnosis, or any other information, services, or product you obtain through this video or others.



Dr. Brett Berner

Upper Cervical Chiropractor in Lutz, FL. Schedule a complimentary consultation: text CONSULT to 813-578-5889 or www.foundationschedule.com