While the COVID-19 vaccine has started making its way to some, we’re still months away before a large portion of the general public will be vaccinated. In the meantime, we want you to stay healthy and safe. According to several reputable studies, some dietary supplements, including melatonin, vitamin D, vitamin K, quercetin and zinc, can fortify your immune system against COVID-19.


In a new study published in PLOS Biology from the Cleveland Clinic, research suggests that melatonin was associated with a nearly 30% reduced likelihood of testing positive for SARS-CoV-2 after adjusting for age, race, smoking history and various disease comorbidities.

See the study: Melatonin a Promising Candidate for Prevention of COVID-19

Vitamin D

Researchers from MLB Medical College in India found a vitamin D deficiency increases the likelihood of a SARS Cov-2 infection turning into a more serious case. A more intense inflammatory response is also increasingly likely in patients with low vitamin D levels. These can lead to increased morbidity and mortality.

See the study: Analysis of Vitamin D Level Among Asymptomatic and Critically Ill COVID-19 Patients and Its Correlation With Inflammatory Markers

In another similar study from Creighton University in Omaha, Nebraska, evidence showed that people with higher vitamin D levels had lower rates of COVID-19 infections and were less likely to contract severe cases that could lead to hospitalization or death.

See the full study: Vitamin D supplements over the winter months can promote health, lessen the effects of COVID-19

Vitamin K

Published by Dr. Rob Janssen, MD and researcher at Canisius Wilhelmina Hospital in Nijmegen, The Netherlands, this study showed that hospitalized COVID-19 patients had lower levels of vitamin K compared to the healthy population control group. Additionally, lower vitamin K levels in patients correlated to a higher mortality rate.

See the study: Reduced Vitamin K Status as a Potentially Modifiable Prognostic Risk Factor in COVID-19


Conducted by Italian researchers, this study showed that quercetin keeps SARS‐CoV‐2’s proteins from binding with ACE-2 receptors, which blocks the virus from infecting human cells. Research also showed that quercetin can directly neutralize viral proteins that help replicate SARS‐CoV‐2.

See the study: A Role for Quercetin in Coronavirus Disease 2019 (COVID‐19)


Led by doctors from Hospital Del Mar in Barcelona, Spain, this study showed that low levels of plasma zinc are associated with poorer survival outcomes in hospitalized COVID-19 patients. When patients had a plasma zinc level lower than 50 mcg/dl at admission, the study found they were 2.3 times more at risk of in-hospital death compared with the patients who had a plasma zinc level of 50 mcg/dl or higher.

See the study: Low zinc levels at clinical admission associates with poor outcomes in COVID-19

Should you decide to incorporate any of these supplements into your wellness routine, please contact your physician to discuss personalized dosage recommendations.

The Pharmaca team is preparing to receive the COVID-19 vaccine and will administer it in adherence to CDC guidelines. If you have any questions in the meantime, please visit our COVID FAQ page and check back for updates.