Vitamin D and COVID: More Noise Than News
Last year, when we didn’t have many great options for dealing with COVID-19, interest in vitamin D was keen. A number of studies found a correlation between vitamin D levels and COVID risk. So splashy headlines ensued. Even the former president and Tony Fauci told us they were taking it. But in retrospect, those headlines about vitamin D and COVID were more noise than news.
We now have better options for dealing with COVID – the vaccines – and the frenzy has calmed down.
What the Evidence Says
In Nutrition Journal, a new systematic review and meta-analysis turned up eleven cohort studies and two RCTs of vitamin D and COVID. More than half a million patients were in the cohort studies. The endpoints were COVID-19 infection and death. The overall quality of evidence was very low.
Jie Chen and colleagues found no association between vitamin D deficiency and infection. None for deaths in hospital, either. There was no dose-response relationship between vitamin D levels and risk of infection or death. Supplementing with vitamin D had no effect on death or ICU admissions.
So the fact remains that vitamin D is an essential nutrient. If you’re deficient, adding it to your diet or taking a supplement makes sense. But it won’t save you from COVID. Vaccines will.
What We Can Learn?
Vitamin D has a big fan club, ready to seize on any shred of evidence – however flaky – to promote it as the cure for whatever ails us. It’s also true that plenty of people are deficient and can improve their health by taking a supplement of it at a reasonable dose.
Beyond those basic facts, there’s another lesson for us in all the noise about vitamin D and COVID that came to nothing. Narratives are powerful. The vitamin D fan club was ready to tell a story that made some sense, but more importantly, captured people’s imaginations.
Good scientists stick to the data. But for persuading people to embrace the knowledge that comes from science, we need more than just data. That data must become part of a simple, compelling narrative. Conspiracy theorists are good with narratives. Science communicators must be better.
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November 15, 2021