Published on August 27, 2021

Video Friday: In this interview, Dr. Paul Marik discusses vitamin D and melatonin as two useful supplements included in his COVID-19 prevention and treatment protocol

In the video featured today, Dr. Mobeen Syed interviews Dr. Paul Marik, MD, about vitamin D and melatonin, and how they may help with COVID-19.

Dr. Marik is currently Professor of Medicine and Chief of Pulmonary and Critical Care Medicine at Eastern Virginia Medical School in Norfolk, Virginia, and is board certified in Internal Medicine, Critical Care Medicine, Neurocritical Care and Nutrition Science. Dr. Marik is the 2nd most published critical care physician in the world, having written over 500 peer-reviewed journal articles, 80 book chapters, and four critical care books; he has already co-authored 10 papers on therapeutic aspects of COVID-19. He has been cited over 43,000 times in peer-reviewed publications and has delivered over 350 lectures at international conferences and visiting professorships. Dr. Marik has received numerous teaching awards, including the National Teacher of the Year award by the American College of Physicians in 2017. Dr. Marik is also a founding physician of the Front Line COVID-19 Critical Care Alliance, which began in March 2020 to develop treatment protocols to help prevent the transmission of COVID-19 and improve outcomes for patients ill with the disease. Among the therapeutics included in these protocols is vitamin D!

As Dr. Marik states in the video below, “it remains mysterious to me why we do not promote the widespread use of vitamin D – it is safe and it appears to be very effective for both preventing and treating SARS-CoV-2.”

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After watching the video, be sure to make note of our added details below!

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Dr. Mobeen Syed Interviews Dr. Paul Marik

Here is a quick summary of what this video discusses, along with additional information and details from GrassrootsHealth:


  • Among the therapeutics recommended by Dr. Marik for COVID-19 are vitamin D, vitamin C, quercetin, zinc and melatonin


  • Vitamin D has shown much promise for decreasing the risk of COVID-19 infection and severe COVID-19 disease, including death

Click to Enlarge & Print

  • As can be seen in the chart above, as vitamin D levels rise, the risk of testing positive for COVID-19 decreases. Specifically, from 20 ng/ml to 55 ng/ml vitamin D, there was a 47% lower positivity rate. As Dr. Merik states, based on this data and more, “why the heck are we not supplementing deficient people with vitamin D?!”



Melatonin May Also be Helpful for COVID-19


  • Melatonin is a powerful anti-oxidant and has been shown to have anticancer effects and play a role in regulating blood pressure and glucose levels


  • Melatonin is also highly anti-inflammatory, with an extensive list of physiological actions


  • Studies have shown a lower risk of SARS-CoV-2 infection and lower mortality among patients taking melatonin

Make Sure You Are Getting Enough Vitamin D and Other Important Nutrients

Having and maintaining healthy vitamin D levels and other nutrient levels can help improve your health now and for your future. Choose which to measure, such as your vitamin D, omega-3s, and essential minerals including magnesium and zinc, by creating your custom home test kit today. Take steps to improve the status of each of these measurements to benefit your overall health. You can also track your own intakes, symptoms and results to see what works best for YOU.

Enroll and test your levels today, learn what steps to take to improve your status of vitamin D (see below) and other nutrients and blood markers, and take action! By enrolling in the GrassrootsHealth projects, you are not only contributing valuable information to everyone, you are also gaining knowledge about how you could improve your own health through measuring and tracking your nutrient status, and educating yourself on how to improve it.

Help everyone Move Research into Practice with vitamin D and other nutrients! As a special birthday gift to everyone, in honor of the science, we have created a special scholarship fund for anyone to donate to that will go towards helping others participate. Your donation will allow anyone to get help with funding their participation when they need it.

Text-to-give: Text Daction to 44321 to add to our Scholarship Fund.

What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?

Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.

STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.

STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).

STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.

STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.

STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.

STEP 6 – Adjust, Repeat…

Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.


The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.

These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.

Review the Latest Nutrient Research for COVID-19

GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:

  • Vitamin D
  • Omega-3 Index
  • Essential elements magnesium, selenium, and zinc
  • hsCRP

Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!

Please let us know if you're interested in helping sponsor this project.

CLICK HERE for updates and new information about the project.

Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called

For each specific supplement, you can track what days you take it, how much, and many other details.  This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!