It is important to understand that vitamin D levels are bit complicated matter, and even doctors aren't agreeing how much is too much (and how low level is "deficiency"). Some of that you can see in article
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7745884/ Note also, that the best form is D3, while D2 isn't recommended. Another article of interest:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912737/
For me it seems that having in blood level of <30 nmol/L (or <12 ng/mL) is clearly indicating deficiency. And 30 ng/mL (75 nmol/L) is sufficient - and that is supported by authors of the article I mentioned. Over that level the "risky zone" starts, but there is no clear consensus about what is the exact limit of too much. I would like to propose targeting 20-30 ng/mL or 50-75 nmol/L range, if your MD doesn't protest excessively and give good reasons to his/her protests
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Therefore it is a good idea to go for a blood test, and after that decide if 2000 IE or 4000 IE or something else is the right daily dose. According to some articles I have seen, the individual variation in utilization of orally taken D3 seems to be quite large. Therefore what's maybe too much for one person, may be just right or even too little for another!
By the way, D3 vitamin is eliminated from body very slowly, and you don't need to take it every day. I have sometimes bought for example 5 000 IU capsules, and then taken those every second day. Average was then 2500 IU/day. Next time maybe 10 000 IU, taking every three days for 3333 IU effective daily dose.
-Teddy