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NMU – 229 Vitamin D and COVID-19 Update

Nutrition/Natural Medicine Update No 228 (February 1, 2022)

with Dr. James Meschino


Topic: Vitamin D and COVID-19 Update

Source: Medscape Expert Panel Interview (January 10, 2022)


On January 10, 2022, three vitamin D experts met for a panel discussion to provide an update on vitamin D as it impacts certain aspects of human health. One of the topics covered was the influence of vitamin D in protecting us against COVID-19 infection, morbidity, and mortality. The panel moderator was Dr. Pam R. Taub – A cardiologist and professor of medicine at the University of California, San Diego. One of the panelists was Dr. Michael Holick – A professor of medicine at Boston University. He was the first to identify the major circulating form of vitamin D in human blood as 25-hydroxyvitamin D3. Over the past four decades, he’s led many of the studies demonstrating the benefits of vitamin D and is responsible for bringing vitamin D to the radar of healthcare professionals The other panelist was Dr. JoAnn Manson – Another luminary in the field of vitamin D research, and a professor of medicine at Harvard Medical School. She’s been involved in many landmark clinical trials that have changed clinical practice, including the Nurses’ Health Study, the Women’s Health Initiative Study, and the more recent VITamin D and OmegA-3-Trial (VITAL study)

The moderator, Dr. Pam Taub made this statement and posed this question to the panelists “There’s a large amount of data that shows low vitamin D levels are associated with patients who have more complications from COVID-19 and are in the ICU. What are your thoughts on supplementation with vitamin D for everyone? Because we all want to have fewer complications if we acquire COVID-19.”

Part of Dr. Holick’s reply included, “We initiated studies almost immediately (after the pandemic began). We worked with Quest Diagnostics and looked at more than 191,000 COVID-positive patients throughout all 50 states, all ages, ethnicities, and latitudes, and showed that if you have a blood level of 25-hydroxyvitamin D of 20 ng/mL (50 nmol/L) compared with 34 ng/mL (85 nmol/L) you had 54% higher risk of acquiring the infection. We know that vitamin D does have an important role to play in immunomodulation and that the COVID-19 infection causes the cytokine storm. The thinking is that the active form of vitamin D can help to downregulate cytokines that are damaging and improve cytokines that can help. We’ve done a couple of studies. The first was in Iran and included more than 200 patients coming into the hospital, including 74% with serious infections. When we looked at their baseline blood levels of 25-hydroxyvitamin D and their outcomes, there was a significant decrease in morbidity and mortality. In fact, among those over the age of 40, there was more than a 50% reduced risk of dying of the infection simply by being vitamin D sufficient at the time they went into the hospital.” “We did a study at Boston Medical Center and looked at patients coming to the hospital. We got their baseline blood level and then followed them for their morbidity and mortality, and again, showed very significant differences. Those who were deficient had more significant morbidity and mortality.” “We do believe that improving vitamin D status throughout your life can help reduce the risk for infections and COVID-19.  More importantly, patients going into the hospital, if nothing else, should be treated with vitamin D almost immediately. “[Editor’s note: Citation identified as Charoenngam N, Shirvani A, Holick MF. Vitamin D and its potential benefit for the COVID-19 pandemic. Endocr Pract. 2021;27:484-493. Epub 2021 Mar 17.]

“There are many biological mechanisms that have been shown for vitamin D to be important in boosting immune response as well as tamping down inflammation and immune modulation, which are mechanisms that are very relevant to preventing severe COVID-19 infection.”

 Dr Manson chimed in with the following statement, “During a pandemic if anything, we would want to err on the side of encouraging more intake of vitamin D because we do think it’s very safe. One of the lessons from the VITAL study was that 2000 IUs today were virtually free of adverse events for 5.3 years. It had a very good safety profile. During a pandemic, why not recommend that everyone ensure they’re outdoors, getting sun exposure, being physically active, as well as maybe taking a supplement of 1000 or 2000 IUs a day?  I think that’s quite reasonable. We are doing a trial right now called the Vitamin D for COVID-19 trial (VIVID). We’re in the process of recruiting, with several hundred people enrolled already, and we hope to have close to 2000 participants overall. We’re looking at vitamin D supplementation started right after the diagnosis: high-dose supplementation 10,000 IUs a day for 2 days as a loading dose, then 3200 IUs a day for 4 weeks. We are looking to see whether that will reduce the severity of symptoms, the risk for hospitalization, the need for healthcare visits, and outcomes of that nature. We hope to have the results at the end of this year or early 2022. I think these randomized trials are very important, but I do agree that recommendations should go out to the general public to avoid vitamin D deficiency at all times, but particularly during a pandemic when there is promising evidence for vitamin D being a benefit.”

Dr. Holick: I certainly think that following the Endocrine Society practice guidelines is a reasonable approach. They recommend for all adults 1500-2000 units a day. They recognize that if you’re obese, you need two to three times more. For my patients, I typically have them on 3000-5000 units a day. For children, the recommendation is 600-1000 units a day. I think that that’s very appropriate. Teenagers, I think, should be treated like adults and they should be getting 1500-2000 units a day. Finally, I personally take 6000 units a day; my blood level is 72 ng/mL (180 nmol/L). I like for my patients to be in the preferred range recommended by the Endocrine Society of 40-60 ng/mL, (100 – 150 nmol/L) and up to 100 ng/ml (250 nmol/L) is perfectly safe.

Dr. Meschino: But I would caution you about this, as various studies have shown that having a blood vitamin D level above 140 nmol/L (56 ng/mL) actually weakens the part of your immune system that makes antibodies (adaptive immune system) and makes you more prone to infections. It appears that Dr Manson agrees with me as we see in her follow-up statement:

Dr. Manson: I would say that the recommendations need to vary according to the health status of the person. During this pandemic, I would err on the side of recommending more vitamin D. Currently, I would recommend, even on a population-wide basis, 1000- 2000 IUs a day.

To sum up, vitamin D experts seem to agree that more optimal vitamin D status can help to prevent COVID-19 infection, reduce its severity and reduce risk of dying from this infection.  More studies are being conducted but it seems prudent to maintain and blood vitamin D level between 85-140 nmol/L (30-52 ng/mL), which usually entails supplementing with 1,000 – 2,000 IU per day of vitamin D. Some individuals need higher amounts to achieve this blood level. The best thing to do is to see your doctor, get your blood vitamin D evaluated and then decide with your health practitioner how much vitamin D supplementation is best suited to your case. I hope this was helpful.

I have included the reference for this panel discussion in the text below.



Excerpts from Medscape Interview Published January 31, 2022: Beyond Bone Health: Does Vitamin D Have a Role in Cancer, CVD, and COVID?


Eat Smart, Live Well, Look Great,

Dr. Meschino

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