Could you link them? I got me tested. My vitamin D level is low, but my doctor told me 1.000 IU per day is too much and I should take 1.000 IU only every other day.
https://pubmed.ncbi.nlm.nih.gov/30611908/
> In summary, long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe.
https://www.mayoclinicproceedings.org/article/S0025-6196(15)...
> The evidence is clear that vitamin D toxicity is one of the rarest medical conditions and is typically due to intentional or inadvertent intake of extremely high doses of vitamin D (usually in the range of>50,000-100,000 IU/d for months to years).
You can find more sources by scrolling down to the "summary" section, https://www.foundmyfitness.com/episodes/jre-1474