How long does it take for Vitamin D levels to fall to "deficient" levels from healthy levels? If you don't supplement and stay quarantined inside for a week in the winter, what effect does that have on your levels?
We are under lockdown pretty much here. So I havent' gone out to bars and shops in months. But I still try to go outside, even if just for a walk in the park most days.
You'd have to be spectacularly unlucky catching it outside if you are keeping a reasonable distance from other people and avoiding hanging around crowds for prolonged periods.
In large dense American cities there are risks with even going outside on a walk. There are stories of people who didn’t leave their homes except on walks but caught COVID-19. There was a NYT columnist who got it and hadn’t done anything except go on walks in NYC. That seems statistically odd to me, because there can’t be that many NYT columnists.
Consider that to go outside, many in a large city must leave their flat, walk down a shared hallway, walk past other people’s front doors, use an elevator, etc.
There’s also a lot of people on the sidewalk, many without masks, who will walk right past you, often talking loudly on a cell phone. It’s often not possible to avoid walking close to these people due to small sidewalks and busy city streets.
Obviously the risk is lower than other activities but it’s not the same as going outside in the suburbs or driving somewhere. In my city, on a 40 minute walk I pass several hundred people. In my building here, none of the other residents wear masks and to enter and exit I must walk past their front doors.
So I would say it’s quite safe. But it’s not quite as safe in big, dense American city as in the suburbs.
A second anecdote. I live in NYC. I've been going on walks, hanging out in the park, going out to eat, stayed in a couple of cabins over the weekend, taken ride shares, dined inside, and traveled on airplanes twice. I don't have the antibodies and I've never tested positive.
My wife goes to work in an office every single day. Doesn't have antibodies, never tested positive.
I'm guessing they from the US. Here we have had absolutely terrible communication from all authorities regarding outdoor activities. It's heavily frowned up to do anything outside of staying inside.
It's surely possible to take too much, but it's a lot. A typical over the counter tablet is 500-1500 IU of Vitamin D. Here[1]'s a study giving an oral dose of 100,000IU to a hundred people, and here[2]'s a paper suggesting muscular injections of 600,000IU in 10 people showed no evidence of metabolic abnormality. The Mayo Clinic[3] site says:
> Taking 60,000 international units (IU) a day of vitamin D for several months has been shown to cause toxicity. This level is many times higher than the U.S. Recommended Dietary Allowance (RDA) for most adults of 600 IU of vitamin D a day.
That's 100x the recommended dose, every day, for months. Were you using powdered vitamin D instead of protein powder by mistake or something?
Deva Boone’s blog (an MD featured often on HN) describes a case where an extra 5000IU supplement caused neurological problems.
IIRC, there was no regard to other sources - e.g. she might have gotten 30,000 other IU per day from Milk and another amount from fish. Very unlikely - much more likely that something else made it toxic in that case.
Regardless, it is clear that the upper safe limit has significant variance and is not well characterized.
(Personally have been on 10,000IU daily for the past 7 years with no ill effects and possibly good effects, n=1 standard disclaimer)
How much a person can take without producing symptoms varies. My threshold was much lower than average probably because of chronic infections, e.g., Lyme disease.
Anyone taking substantial doses of vitamin D (>2000IU daily) should probably be getting regular blood tests to monitor their vitamin D levels. Vitamin D can accumulate in fat and the liver.
