A little difficult to say.

This is my favorite brand:
https://www.ebay.co.uk/itm/404031270073
It is in oil-filled capsules format, and presumably that kind of oil-filled soft-gel format absorbs better than "dry" tablets.
I have found NuU to be reliable also for many other vitamins and supplements, including Calcium-Magnesium-Zink.

BTW. D-vitamin is not eliminated from body as fast as water-soluble ones, it takes days. You could therefore even take a stronger one such as 10 000 IU three times a week for same dosage and effect.

Take care,
Teddy