Vitamin D and COVID-19: What We Know at This Time

Vitamin D is essential for normal human functioning, but just how much is necessary has been a subject of debate and whether supplementing vitamin D in people who have “normal” levels can be beneficial in the prevention or treatment of certain diseases has been a subject of controversy for decades, largely due to the lack of high-quality studies.

While some will argue that the level of normal vitamin D should be set higher than current guidelines, I think that you would find a general consensus that an adult is vitamin D deficient if their serum 25-hydroxyvitamin D level is < 50 nmol/L or 20 ng/ml. There would also likely be agreement that treatment with vitamin D supplementation in individuals with serum 25-hydroxyvitamin D levels of < 30 nmol/L or 12 ng/ml is beneficial and very important for overall health.

Many people promoted the need for vitamin D supplementation to prevent and/or treat COVID-19 when the pandemic first began (in fact, a number of people continue to promote this idea). Unfortunately, we had little data or clinical studies at that time to answer that question. However, two years later, we know a lot more. Here are some key points:

  1. A study from Italy showed that a low serum vitamin D level was an independent risk factor for developing severe COVID-19 (mean 18.2 ng/ml) and dying (mean 13.2 ng/ml) from it, if a patient with low vitamin D gets infected.
  2. Unfortunately, studies have not been able to demonstrate that giving high doses of vitamin D once the patient with low vitamin D gets infected will reverse the risks for severe disease, hospitalization, the need for intensive care, mechanical ventilation or death.
  3. Some persons have a genetic abnormality that causes them to have high levels of vitamin D, but studies have demonstrated that these folks do not have a lower risk of getting infected or if infected, having less severe disease or risk of hospitalization and death.

Guidelines from the Endocrine Society recommend the following dietary intake of vitamin D:

  • Children aged 1-18 years: ≥ 600 IU/d
  • Adults aged 19-70 years: ≥ 600 IU/d
  • Adults older than 70 years: ≥ 800 IU/d

So, above, I have provided you with the state of the science. But now, here are my thoughts and how I put all this together:

  1. If you have vitamin D deficiency, it makes sense to take a daily vitamin D supplement. My vitamin D levels have been low and I take a daily supplement. If you have low levels of vitamin D, you may be at higher risk if infected.
  2. The fact that people with low vitamin D levels are at increased risk for severe disease if infected, but supplementing with vitamin D once infected doesn’t improve outcomes, as well as the fact that those with high vitamin D levels are not protected from developing severe disease suggests to me that vitamin D is likely only one factor in this risk for severe disease and may not even be the most important factor. Thus, if you get infected, please don’t rely on vitamin D and other supplements to keep you from getting severely ill. Seek medical attention from a physician and explore options that have been proven to improve outcomes if you are at high risk for severe disease, such as antiviral medications and monoclonal antibodies. I have no objection to taking vitamin D if you get infected, my point is simply that you should not rely on vitamin D or any other supplements to keep you from getting severely ill.

12 thoughts on “Vitamin D and COVID-19: What We Know at This Time

  1. Can getting some sunshine on a regular basis help prevent vitamin D deficiency, and thus help protect against severe COVID-18 infections?


  2. Great blog. Thank you telling this. I hope all those I copy will read and hear the message DuWayne Sent from my iPhone



  3. Dr. Pate
    I heard you speak on Idaho matters today. It was informative and refreshing to hear someone speak as honestly and clearly as you do. It has been more and more difficult to understand what is true these days. Thank you so much for your contributions.
    B. White Eagle


    1. Thank you so much for taking the time and making the effort to provide me with this comment and the encouragement. I greatly appreciate it. And, thanks for following my blog!


  4. Hi Dr. Pate,

    What are your thoughts with regard to immunocompromised people getting a 4th dose of the Pfizer vaccine? With the positivity rate on the decrease and continuous COVID19 treatment advancements, is there any reason to wait?

    I really appreciate the great service you provide for our community. Thank you, thank you!


    1. Thanks, Don. Great question. I think that this is exactly the right time to get your booster. Getting a booster during the next surge means you will be at increasing risk for a period of 7 – 14 days as disease transmission is rapidly increasing. Getting boosted now means you will be protected for the next surge. I wish that I agreed with those who are saying that we won’t see any more surges or at least we should have smooth sailing until this fall/winter, but I don’t believe either of those scenarios are likely. Right now, I only feel confident in saying I don’t think we will have another surge in the next 1 -2 weeks. I hope it is much longer, but certainly can’t guarantee it.
      Thanks for your comment and your question and thanks for following my blog!


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