1000 IU of vitamin D (per kg) can indeed be toxic – 1947
There were many studies in the 1940’s stating that
1000 IU of vitamin D per kilogram of body weight was toxic.
The average weight of an adult was approximately 70 kg, so yes, I agree, 70,000 IU of vitamin D can be toxic.
I had often wondered why doctors had been told that 1,000 or 2,000 IU of vitamin D was toxic.
My guess is that the old message was trimmed to 1,000 IU of vitamin D is toxic,
Note in the clipping belows that even 35 X higher was sometimes not toxic.
📄 Download the 1947 PDF from VitaminDWiki
Here is the actual text from the 1947 article

See also VitaminDWiki
Vitamin D stigma in the 1980's established toxic level as 1000 IU a different story, same outcome
NHS (UK) mistakenly says more than 1000 IU of vitamin D can be harmful – Dec 2013
Note: 1000 IU per kg IS NOT toxic if you drink a lot of water, minimize Calcum, and take the cofactors
1000 IU per kg Vitamin D for autoimmune diseases – Coimbra Aug 2013