Bowl of Vitamin D

High-Dose Vitamin D for COVID-19 Flunks Again

The COVID-19 pandemic has taught us many things, big and small. One of the unexpected insights is the fervor that exists for vitamin D. It’s a potent vitamin with many effects. Too little of it in a person’s body can cause any number of problems. Too much can be a serious problem as well. It really is that simple. But somehow there’s an impulse to take it further – to believe it must have great therapeutic value in any number of conditions. The latest version of this is the belief that high-dose vitamin D might be therapeutic for COVID-19.

Alas – a new, rigorous RCT appearing in JAMA yesterday dashes those hopes.

A Valuable Null Study

To publish a null study can be quite a challenge. People want to read about discoveries and breakthroughs. Not disappointments. But it’s important to know what doesn’t work so that clinicians can devote their time and attention to more effective care.

So this study by Igor Murai et al is valuable, especially in JAMA. It was previously available as a pre-print, without the benefit of a rigorous peer review.

These researchers randomly assigned 240 hospitalized patients with COVID-19 to receive 200,000 units of vitamin D or a placebo. Their illness was moderate to severe when they received it. The primary outcome variable was the length of hospital stay. Getting vitamin D made no difference. The average hospital stay was 7.0 days regardless of whether a patient received vitamin D or a placebo.

It also made no difference in ICU admissions, the need for mechanical ventilation, or the risk of death.

Same Song, Another Verse

This is a very familiar pattern for vitamin D, write David Leaf and Adit Ginde an an editorial alongside this study:

“Multiple lines of evidence in support of a potential therapeutic role for vitamin D generated enthusiasm over the past decade for testing whether administration of large doses of vitamin D might improve outcomes in various groups of patients, including those with critical illness.

“Randomized clinical trials testing vitamin D3 administration as a therapeutic strategy for disease prevention in other settings have yielded similarly null results.”

No doubt, true believers will continue to pursue the dream of proving that vitamin D can cure any number of problems. We will keep an open mind. But for now, we’re sticking with the idea that it’s useful as a supplement in modest doses (400 to 800 units daily) if you might not be getting enough from food or sunlight. For more serious problems, don’t expect miracles.

Click here for the study and here for the editorial. For further perspective, this item from JAMA describes the challenges of sorting through speculation about Vitamin D and COVID-19.

Bowl of Vitamin D, photograph © Ted Kyle / flickr

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February 18, 2021

5 Responses to “High-Dose Vitamin D for COVID-19 Flunks Again”

  1. February 19, 2021 at 10:34 am, David Brown said:

    A single dose of vitamin D3 is inappropriate for patients with COVID-19 complications. This research is nothing new.

    • February 19, 2021 at 10:38 am, Ted said:

      Indeed. It’s a good idea to make sure you’re getting enough vitamin D every day. For many reasons. But acute dosing after someone gets COVID-19 doesn’t appear to do much.

  2. February 19, 2021 at 1:07 pm, Jerome Dixon DO, MNS said:

    Vitamin D is Suppl. not a therapy. Its preventive benefits to general health, prevention & immunity are without challenge. Vitamin D is a neurohumeral-endocrine-immune modulator with proven benefits throughout the human body. Trying to use it as an acute medical therapy is asking a bit much and trying to treat it as a drug, which it is not. Using nutrition as an acute therapy vs. a remedy for chronic illness are two completely different things. Why do people with good medical backgrounds keep trying to do junk science, in an effort to try and prove a null hypothesis that they already know the answer to, is just a waste of good $$$ and it confuses those who do not understand what good science is. Us of Vit. D. and other nutrients in an acute setting is helpful to the host but it is disingenuous to ask these therapies to do more than to support the host human’s system if fighting back as the pharmaceutical therapies do their job.

  3. March 03, 2021 at 1:39 am, stratunalia said:

    First of all, no research should conclude with a definite answer. Secondly; this study was done in Brazil, where people already get sun exposure, so their levels were not so low and a mere 200 000 units could make a difference; thirdly, what was the quality of vit D3? was it synthetic? How much do we know about the absorption of synthetic D3? Then, What were the other drugs administered to the patients? Could they have impaired kidney function and affected Vit D3 absorption? And finally: Are levels of 24.0 ng/mL and 26.9 ng/mL respectively “optimal?” This study recommends between 40 and 60 ng/mL for both children and adults.”

    • March 03, 2021 at 2:58 am, Ted said:

      Thanks for sharing your view.