Vitamin D Helps with Respiratory Infections – But COVID?

Croissance!Public enthusiasm for vitamin D during the COVID pandemic has been impressive. An ardent fan base follows every twist and turn in this saga. Observational studies find lower risk in people who have higher vitamin D level. Then an RCT comes along to muddy the water by finding no benefit.

Two new studies provide new encouragement for the fan club. But if you look closely, you’ll realize that there’s nothing new here – and no assurance that vitamin D will save you from COVID.

Another Correlation Study

JAMA Open Network published another correlation study that found a significant association between higher vitamin D levels in Black individuals and their risk for COVID-19. They found no correlation in White individuals.

Researchers concluded merely that this needs more study. But that didn’t stop the press office at the University of Chicago Medical Center. “High vitamin D levels may protect against COVID-19, especially for Black people” was the bold headline on a press release. It would have been accurate if the headline said “may or may not protect,” but that would not have been so splashy.

Some Real Protection from Respiratory Infections

More meaningful is a new study in Lancet Diabetes and Endocrinology. David Jolliffe completed a systematic review and meta-analysis of randomized studies testing vitamin D supplementation to prevent respiratory infections. They found a significant effect. In fact, they saw a roughly 20 to 30 percent reduction in respiratory infections when people took daily supplements of vitamin D. The doses ranged from 400 to 1,000 units daily. The authors explain that the benefit appears to be real, but small. They also note that any relevance for COVID-19 is, as yet, unknown.

But Don’t Count on Vitamin D for Protection from COVID

Getting enough vitamin D can indeed help a person’s health. But by now, it’s obvious that it is not our best bet for protection from COVID-19. When people decline a COVID vaccine in favor of taking vitamins, they are putting themselves at risk. Vaccines currently approved in the U.S. are 100 percent effective for preventing serious illness and death from COVID-19. Even seriously flawed and cherry-picked data for Vitamin D shows no such benefit.

So we hope that the recent infatuation with vitamin D to prevent COVID-19 is fading, as Google Trends data might suggest. While this vitamin is good for health in reasonable doses, it’s no substitute for better measures like vaccines, masks, and physical distance to prevent COVID-19.

Click here for the study in JAMA Open Networks and here for the study in Lancet.

Croissance! Poster from Library and Archives Canada / flickr

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April 2, 2021

2 Responses to “Vitamin D Helps with Respiratory Infections – But COVID?”

  1. April 02, 2021 at 9:04 am, David Brown said:

    400 to 1,000 IU of vitamin D is hardly enough to furnish substantial protection from cold and flu viruses. “The latest International studies indicate that a blood level of more than 30ng/ml (75nmol/L) is a level that indicates protection against serious or fatal Covid-19 infection. A target level of 40ng/ml (100nmol/L) would appear to be appropriate, and to achieve this vitamin D in a daily supplement of 4,000 units is effective, perfectly safe, and costs about £12 per year.”

    To be sure, people of color are more vulnerable to COVID-19 infections and complications than light-skinned individuals.

    However, this difference disappears when vitamin D sufficiency is achieved.

    The controversy could be resolved using newly developed technology.

    • April 03, 2021 at 6:32 am, Ted said:

      David, the references you are citing link to opinions, anecdotes, and observational reports. Not evidence that vitamin D provides protection from COVID-19. So the fact remains, that it’s a good idea to make sure you have adequate levels of vitamin D. But it won’t protect a person from COVID like a vaccine, mask, and social distance will.