[endless1234]

But it's also pretty hard to take too much of it - ref eg https://www.health.harvard.edu/staying-healthy/taking-too-mu... - and the supplement doesn't cost much at all

[nextaccountic]

Also, there is some evidence that Vitamin D supplementation at higher than natural, higher than usually recommended levels is beneficial to mental health (but not sure if the OP article confirms it)

[knownastron]

Do you know where you heard of this link between high Vitamin D levels and improved mental health? If you do, can you share it?

[pydry]

I've gotten wildly different estimates about how much to take - including some that overlap with how much is supposed to be harmful.

Some people say 500 IU is enough, some say you need 4000 IU per day.

[nradov]

There's no way to know without testing. The optimal supplement amount for you could be zero, or it could be even more than 4000 IU per day. This depends on genetics, diet, ultraviolet light exposure, body composition, and a variety of other factors. So, the only way to be sure is to get periodic blood tests and titrate the supplements up or down to hit the target level.

If you don't want to hassle with testing then something like 600 IU will be adequate (although not necessarily optimal) for most adults. YMMV.

https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona...

[knownastron]

This says 30,000 to 50,000 IU is fine: https://vers.substack.com/p/doctors-are-idiots-vitamin-d-meg...

[colechristensen]

It's not hard to take too much.

They sell 5000 IU vitamin D pills, with regular supplementation my serum levels were at the top of the range which led me to ease off.

You can take too much and there are consequences, it screws with your calcium which eventually screws with your nerve firing.

[voldacar]

If you look at the literature on cases of D "toxicity" (hypercalcemia), it only really occurs when people take absurd doses like 100k IU per day (often far more) for months. This usually occurs by accident, rather than someone choosing to take that much. And since D toxicity isn't reported that often, I have to assume that there are a lot of people out there unwittingly taking mega doses but without developing toxicity. But everyone thinks that high doses of D are scary because of that idiotic 4000 IU number that gets thrown around. N=1, but I take 50k IU per day and have never had any issues. My calcium is within the normal range.

[jghn]

One of the claims is that what's considered normal range is already too low. I'm not personally equipped to tell you if that's right or wrong. But when people are suggesting to take megadoses they're coming from this angle, whether they realize it or not.