Published on January 26, 2021

97% of critically ill COVID-19 patients presented with vitamin D levels below 20 ng/ml (50 nmol/L) vs 32% of asymptomatic patients

Vitamin D is essential for maintaining a proper immune response – from helping immune cells to carry out specific functions during an infection and modulating the genetic expression of immune cells, to having a direct effect on the lungs and inflammation, vitamin D has been shown to decrease the risk of respiratory infection, complications from acute respiratory distress syndrome (ARDS), and COVID-19.

Once infected with the SARS-CoV-2 virus, approximately 30-40% of people experience only mild symptoms of COVID-19, 40-45% do not develop any symptoms, and fewer than 15% of cases become severe. Several risk factors have been identified that contribute to the increased risk of severity and death from COVID-19, including obesity, diabetes and hypertension. Vitamin D deficiency has also shown to be a significant, independent risk factor for COVID-19 severity, and thankfully, it is easy to identify and treat.

Vitamin D Levels Among Asymptomatic vs Critical COVID-19 Patients

An observational study by Jain et al. looked at 154 patients positive for COVID-19, ages 30-60 years old, who were admitted to a tertiary COVID-19 care center over a span of 6 weeks in 2020. Of the patients, 91 were asymptomatic, displaying no symptoms over 12 days from testing positive. These patients were compared to 63 others who developed severe enough symptoms to require admission to the Intensive Care Unit (ICU). Overall, those were critically ill and admitted to the ICU were more likely to be male and were older on average.

Vitamin D levels were compared between the groups and the difference was found to be highly significant (p=0.0001). The average vitamin D level in the asymptomatic group was 28 ng/ml (70 nmol/L) with 29 patients (32%) having levels below 20 ng/ml or 50 nmol/L (labeled as being deficient). The average vitamin D level in the critically ill group was 14 ng/ml (35 nmol/L) with 61 (97%) below 20 ng/ml. The pie charts below clearly show the break-down of those whose vitamin D levels were deficient in the asymptomatic group and the critically ill group.

Click to Enlarge & Print

Inflammatory markers were higher among those with vitamin D deficiency, as was the fatality rate. 21% of the patients with vitamin D deficiency (below 20 ng/ml or 50 nmol/L) died compared to only 3.1% of those without vitamin D deficiency.

In Conclusion

The authors of this paper conclude with recommending “mass administration of vitamin D supplements to populations at risk for COVID-19.” Vitamin D supplementation is safe, inexpensive, and easy to implement, and avoiding vitamin D deficiency has many other health benefits.

The statistics for COVID-19 severity and fatality clearly show a decreased risk with higher vitamin D levels, however, there is no one dose suggestion for everyone (one person may need only 2,000 IU/day while another may need 10,000 IU/day to achieve the same result) – and the ONLY way to know if you are getting enough or getting too much vitamin D is to test your blood level and adjust your dose to reach the scientists’ recommended 40-60 ng/ml (100-150 nmol/L).

Make sure you are getting enough vitamin D and other important nutrients

By joining the GrassrootsHealth projects, you are not only contributing valuable information to our study, but 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. Do you know what your status of vitamin D, omega-3s, and other essential nutrients is? Could your levels be improved? Test now to find out!

We now have a NEW GIFTING SERVICE that allows you to quickly send ‘Gift Cards’ to friends, family and coworkers who you consider might need immediate access to testing, and to Claim the Joy of Your Health TODAY. Give the gift today!

What does the Research Say about Vitamin D & COVID-19?

It’s TIME to start saving lives! If you can help PREVENT the majority of the death, it’s time! What’s it costing you/us not to take action NOW?

There is much published research that supports a clear link between vitamin D and COVID-19 showing that higher vitamin D levels are related to:

a decreased risk of testing positive for COVID-19

increased viral SARS-CoV-2 RNA clearance

better clinical outcomes among patients with COVID-19

less severe COVID-19 disease

decreased risk of death due to COVID-19

Be sure to educate yourself on the benefits and importance of vitamin D for immune health, and take steps to ensure you and your loved ones are getting enough.

You can review all of the COVID-19 and immune health information we have shared on this page.

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!