What is way too much? I take around 4000IU per day. Which just about brings my blood levels into the “green” area in blood testing.

The reddit post was taking 50,000IU a day, which is usually the amount prescribed for someone to take once a week.

Your 4000IU isn't too much. Lots of the brands you see in stores are 5k for daily supplementation.

> Your 4000IU isn't too much.

By what metric? Jeez. People, you need to get your blood checked. There is no one-fits-all dosage. In winter, 4000 IU/d was enough to raise my blood levels well into the excessive range.

My 4000 units were after blood testing and also after genetic testing which showed some VDR mutations that might benefit from supplementation. As mentioned in another comment, that dose brings me slightly over 30 ng/ml, so basically borderline ok.

I fully agree that supplementation should always be combined with both blood testing and also a general medical evaluation.

FWIW: my functional provider recently noted low levels in my labs and I was already taking 2K IU daily. She bumped me up to 6K UI daily.

4,000 is perfect.

Current recommendations are 800 IU per day if you’re not significantly deficient. Always keep testing at least once a year or so. I took 5000 IU per day for a while, which ended up pushing me over 60 ng/ml. That’s considered too high a level and may have negative health effects.

I tested after taking 4000 IU daily for quite a while and ended up at 30.9 ng/ml, so I guess I have some buffer left. But I fully agree, regular testing is prudent when supplementing anything above common established levels.

Given 10min of sunlight the body can naturally produce 15,000UI equivalent so I think gp is likely astroturfing for that brand

That is actually a low dose.

Yeah, I showed a really mild deficiency in my work so they just suggested adding a low daily dose for me. I wouldn't expect to have had any side effects.

I was very deficient and they gave me 50k UI per day prescription vitamin D3 for 60 days. Sure enough I was high-normal on my next test. 800ui is likely not enough to have any effect unless you consistently take it for years.

That's wild. I've never heard of such a high dose being prescribed daily.

Yes, I wouldn't expect to notice anything on my dose.

It was for 60 days. If they continued to take this much indefinitely it would surely cause troubles, but 60 days when starting from deep deficiency is reasonable.

I was very very low, googling my level 'risk of rickets' came up!

Even that sounds extreme. The "Vitamin D Hammer" for people extremely deficient is 50k IU just once, not even for a temporary period.

It is high, but it's not extreme. 50k IU just once is an equivalent of about 7000 IU daily for a week, which won't really move the needle much if you're seriously deficient (in fact, it's still within what's considered a safe daily dose for healthy people - you can produce more than that from sunlight alone). You can feel free to take your "hammer" weekly, no deficiency required.

When I took >5000 IU daily for three months, I only raised 25(OH) D level in my blood from 9 to 30 ng/ml, and there's no evidence of toxicity below 150 ng/ml.

Of course, when dealing with high doses you need to keep your levels in check, as absorption can differ between individuals.