Indeed - and a good little video it was.
Seconded.
Pretty sure it also said some studies have shown that those with low vitamin d are more prone to getting respiratory infections. Seems reasonable to infer that you're at a greater risk of catching covid-19 too if you have low vitamin d levels, although I guess that's not the same as saying normal levels give you extra protection - more that having normal levels may be required to have a healthy and normally functioning immune system.
It was also suggested that vitamin d plays a role in helping to regulate the immune system making it less likely to go in to overdrive. Again if true it makes sense that this would mean those with very low levels are more likely to suffer the serious complications that can occur and potentially more likely to die as a result.
Anecdotally I suffer from low vitamin d levels, which I found out a few years back after I was persistently ill for about 3 months one winter and went to the docs assuming I'd picked up a virus and couldn't shake it off. After they did bloods the only thing noticeable was I had very low vitamin D. I've taken supplements ever since and haven't had the same levels of winter illness, although I am still prone to getting run down from time to time, which I take as a sign to up my dosage for a few weeks. The docs seem a little 'meh' about the whole thing, as I like to have a blood test done to check vit D levels so I can adjust the amount I'm taking and they generally make me feel like I'm being a pain and wasting their time. Given how infrequently I visit the docs seems a shame that what could be a preventative action is discouraged and they'd rather wait until I get ill to decide maybe something should be done.
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