The critical question remains though- is vitamin D the causal factor, or instead an indicator of something else?
Not really. We should be blasting "get your Vitamin D supplements" from the rooftops, because maybe that's a significant factor in COVID-19 and it's safe and people should get them anyway. There's no downside.
If in a few years it then turns out that Vitamin D had nothing to do with it, it doesn't matter. If it turns out that Vitamin D really was a big factor, we'll be sorry for being hesitant with a safe and cheap intervention.
one cause of vitamin D deficiency is the overuse of sunscreen
sunscreen should be used as protection against sunburn, but not put on all the time in every instance
be outside, stop lathering yourself with sunscreen and get natural, low continuous levels of vitamin D.
supplements may be better than nothing but they far from providing you with the same dose and availability of vitamin D
The generally safe amount is 4000 IU daily, which should get almost everybody to healthy levels. However, if your doctor finds that you have low levels, he may prescribe far higher amounts for a while.
Vitamin D is an easily manufactured supplement, it's not medicine that some people absolutely have to take every day.
Also, we're heading into summer and the sun is still rising every day.
> However the main issue that I think we want to prevent is luring people into a false sense of security that causes them to decrease the proven preventive measures.
We've had the same discussion about masks, so I think that one's settled.
> We don't need large groups of people gathering on beaches because they think the sun will be a miracle cure and they don't have to worry about getting sick.
If you don't want people gathering on the beaches, prohibit it. Having said that, the risk of infection outdoors is generally considered to be quite low.
> So if you want to personally start taking it without changing your behavior, be my guest. But any advice to take it needs to be clear that the evidence it helps is still very suspect at this point.
The evidence that Vitamin D supplementation works is there and it has already been recommended for everyone with low serum levels, well before COVID-19.
The problem is that people often aren't even aware that their serum levels are low, so that is highly prevalent - especially in the elderly and people with darker skin.
The difference between masks and vitamin D is that one is proven to work and one might work. If vitamin D doesn't help as much as people here are claiming, there is a real downside if people are behaving as if it works. That applies to my arbitrary example of beach gatherings as well as other behavior the government has no hope of preventing.
Once again, this doesn't necessarily mean that vitamin D doesn't help. We just need better data. The early indication was that hydroxychloroquine helped too and we all know how that turned out.
Hand washing and social distancing appear to be the most important. That means soap and 6+ feet for at least the next 2 years. That is definitely doable. I don't see masks as a long-term strategy.
When the primary vector of spread is through water droplets expelled while talking, coughing, or sneezing, I would think the importance of reducing the travel distance of those droplets would be self evident.
Without sun exposure, you'd have to be eating several pounds of fatty fish every day to get to "healthy" levels from diet alone. You need a supplement.
Keep in mind, non-severe Vitamin D deficiency doesn't cause any significant evolutionary pressure, so migrating humans just rolled with it - to this day.