Vitamin D was one of the most sought-after supplements as the greater hope of fighting Covid. However, as it turns out when it comes to fighting off the pandemic, it does absolutely nothing. According to the first major study into their effect on the virus, taking vitamin D supplements does not cut the risk of catching Covid or reduce the severity of the symptoms if you do and neither does it reduce the risk of developing long Covid.
A study of 6,200 people, led by the Queen Mary University of London, revealed that the supplements don’t protect against other acute respiratory infections such as the common cold, sinusitis, ear infections, and laryngitis. Professor Adrian Martineau, an academic at the Queen Mary University of London and a respiratory specialist at the Barts Health NHS Trust, who is co-heading the trial, said, “We were surprised and disappointed by the outcome given the work we’d done previously showing vitamin D protecting against other respiratory infections. But it is what it is.”
“If we had known whether it works we wouldn’t have done the trial, so there was a genuine question there and it was well worth doing. It was a big trial and we used a generous dose of vitamin D. We showed that people took it and their levels went up. And the trial was done at such a time when only a tiny number of people were vaccinated initially so we captured enough to see the effect if there was one,” he said.
The government currently recommends 10 micrograms a day, or 400 international units, to protect muscle and bone health. “The government advice on vitamin D isn’t based on any effects on respiratory infection it’s based on proven benefits for bone health and muscle health and those aren’t changed by the results of this study,” Professor Martineau said.
Vitamin D is found in foods such as oily fish, red meat, egg yolks, and liver but in smaller quantities than the immune system needs to function properly.
Prof Martineau said, “There is genuine uncertainty here and the only way to resolve that is by doing the sort of trial that we propose. There is quite a lot of suggestive evidence. There’s a bit of evidence from the lab and there’s the very, very striking observation that the people who tend to get the most severe disease look exactly like the people who are at highest risk of vitamin D deficiency.”
