Since COVID usually kills via pneumonia, and insufficient vitamin D appears to be a surprisingly large risk factor in respiratory infection, it’s probably pretty important to keep vitamin D levels sufficient (which in most people means supplementing it specifically, esp if there’s any quarantine that affects food).
Study says 4x rate of respiratory infection in the very deficient, but doesn’t see an obvious effect in the partially deficient, so slightly weird statistics.
Study says very large effects in children
WHO says linked
Study says no effect from supplementing after already sick, so get on this before infection
Note: In the summary post, this comment thread suggests getting only normal amounts of vitamin D.
From Lifestyle interventions to increase longevity:
There’s also the bad news that multivitamins mostly don’t do anything. There has not been found an alternative to eating a variety of nutrient-dense whole foods. Though vitamin D supplementation appears to be quite beneficial.
(FWIW, I just purchased from the Amazon link!)
It seems to me like this study wasn’t very good and I’ve been more convinced by the rebuttals, such as this one:
Incentive sperometers are often used for the prevention of pneumonia. Maybe this suggests using those as well?
Good call, these are indeed useful, though I’m not sure if worth it. Guessing 20 mins total for vitamin D for a 3x decrease in 10% of the population is roughly a 7% risk reduction, while maybe 10 hours on the spirometer for a ~~3% effect? (Eyeballing this study in pneumonia sequelae looks like an 80% effect from this over 2 years, plus other interventions.) If this thing on average knocks 2 months off my life, a 3% effect is still 2 days, plus you get other health benefits, BUT if I’m planning on quarantining hard enough to not get it, the benefits do go down.
Scott Alexander says Vitamin D is (TL;DR) just good for bone health, even though studies exist saying otherwise.
I’m leaning on the expected value rather than robust evidence.
Definitely seems plausible to me that it’s not useful for immune function outside bone health. But priors (it’s the one vitamin not in diet, so everyone is deficient) and the small amount of evidence are enough to make me think it’s net-positive, and even 20% likely to help by a small amount is a relatively large benefit (~ a day of life).
It seems hard enough to find small effect sizes of things via study that I’m not at all surprised meta-analyses showed no evidence for it—and when I don’t really expect to see evidence, defaulting to “do what seems like it would be healthy in the ancestral environment” says sunlight is probably a better bet than supplements, but being non-deficient in vitamin D is probably a better bet than being deficient. (And again, this doesn’t apply to other vitamins because they’re in the diet. It does apply to e.g. sleep and exercise though.)
What would be the appropriate dose of Vitamin D?
The large effects on children is an odd example (poor example?) to point at since children have been reported to have the least harm from COVID-19.
1000-2000IU on average per day for an adult, depending on your size. You add this up and take it instead every 2-3 days likely without any issues (e.g. I take 3000-4000IU every 2-3days)
If you have lighter toned skin and get regular sun exposure you may not need any supplementation
You can get vitamin D from sunlight exposure. For white people, this doesn’t take long, probably minutes (around noon) of direct exposure on your face and arms. If your skin is darker, it takes longer. You have to expose more skin for longer periods. Black people maybe can’t get enough at high latitude and will have to take the pills. If you’re supplementing this way, you do have to actually step outside for a bit. Exposure through windows that block UV is not going to work. Obviously, sunscreen will prevent some exposure.
If you get a sunburn, you waited too long. You have to factor in season, latitude, time of day, and skin tone. There’s an app called dminder that can help you time it so you don’t get the sunburn.
Is there any reason to worry copper tape might be less effective than the copper used in experiments? (I haven’t read methods to see if they describe the source of the copper) For example, a lot of copper is designed to be resistant to oxidation—does that matter?