Published on August 17, 2021

Study finds significantly higher levels of vitamin D related to a lesser degree of severity and better control of symptoms among asthma patients

Asthma is one of the most common chronic diseases worldwide, and is the leading chronic disease among children. According to the Asthma and Allergy Foundation of America, asthma affects approximately 1 in 13 Americans, with Black Americans being 5 times more likely to have an emergency room visit due to asthma than white Americans, and nearly 3 times more likely to die from asthma.

Many of these deaths are avoidable with proper treatment and care. However, a large portion of patients with asthma do not have adequate control over their condition, even with high-dose medication, which leads to a high risk of severe exacerbations and asthma-related mortality.

Could Vitamin D Level Help Prevent or Control Asthma?

The development of asthma is affected by both the innate and adaptive immune systems, which are influenced by vitamin D in many ways.

Previous studies have indicated vitamin D may be helpful for asthma patients, and have demonstrated a relationship between low vitamin D levels and poorer asthma control, reduced lung function, more frequent attacks, and the need for higher doses of medication. One case control study using 100 patients in a private clinic in Pakistan found that vitamin D (50,000 IU vitamin D3 per day for 30 days) improved FEV1 measurements for asthmatics within two months, and even more by three months. FEV1 is measurement used in testing lung conditions whereby a patient breathes out forcibly on a plastic tube device, called a spirometer, to determine the volume of air they can expel.

Vitamin D Levels Associated with Symptom Severity and Asthma Control

A study by Shahin et al. looked at vitamin D levels among 70 adults with asthma and 20 healthy adults to see if there was a correlation between vitamin D levels and the incidence and severity of asthma.

Patients with asthma were divided into groups according to the severity of their symptoms and their FEV1%. Groups were defined as

  • Intermittent asthma (n=36)
  • Mild asthma (n=8)
  • Moderate asthma (n=12)
  • Severe asthma (n=14)

Another grouping was conducted according to asthma control, defined as

  • Controlled (n=42)
  • Partially controlled (n=15)
  • Uncontrolled (n=13)

Vitamin D levels were categorized as

  • Deficient (below 20 ng/ml or 50 nmol/L)
  • Insufficient (20-25 ng/ml or 50-62 nmol/L)
  • Sufficient (more than 25 ng/ml or 62 nmol/L)

What did the study find?

When looking at vitamin D levels among the different groups of asthma patients,

  • healthy patients had an average vitamin D level of 34 ng/ml (85 nmol/L) compared to asthmatic patients with an average vitamin D level of 20 ng/ml (50 nmol/L, p<0.001)
  • higher vitamin D levels were significantly associated with decreased severity of asthma symptoms and FEV1% (p<0.001)
  • vitamin D levels were significantly lower among those with uncontrolled asthma compared to those with controlled asthma (p<0.001)

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Overall, the study found that patients with severe asthma had an average vitamin D level that was 67% lower than patients with intermittent asthma symptoms, and average vitamin D levels were 49% lower among patients with uncontrolled asthma compared to patients whose asthma was under control.

The authors conclude that “the higher the level of vitamin D, the lesser the degree of bronchial asthma severity and the better the control,” which is in support of other previous studies looking at the relationship between vitamin D and asthma outcomes.

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!