Probably should't go too wild with the Vitamin D3.
It can bump up your calcium levels if you have too much of it. The tolerable upper limit is like 4,000 IU/day so probably don't wanna go above that if this is something you're going to stick with. I'd say you probably don't want to come close to that.
Honestly, you're probably good with 1,000. I think recommendations are around 800-1,000 for people who are not insufficient or deficient so you should probably be good with what you have. Not even sure 1,000 IU has shown to be any more beneficial than 800 IU.
Wanna make sure it is "Cholecalciferol". Pretty sure this is the most beneficial form of Vitamin D out there and may be the only one with proven benefits.