Hello,
Sorry you feel that way powerman. personally, I see 7 responses trying to help you. They may not be the answers you are wanting to hear, but they ARE trying to help.
I wrote the Leopard Gecko Caresheet. I will break it down to an answer I think you wish to see.
Leopard Geckos are one of the species that does well with high calcium intake. As such, it is highly advisable to keep a dish of calcium in the enclosure at all times. (This allows the Leopard gecko the ability to consume the calcium as needed.) If you don't leave a dish in their all the time, and the Leo begins seeking an alternative means (which is common) to compensate for the lack of calcium, they have been known to eat other things. (Particularly substrate material which can lead to an impaction.)
The reason that many people don't bother with vitamin D3 is because it is believed that many reptiles can not absorb it through their food intake. The reason I don't say "Don't use D3 with Leopard Geckos" in the caresheet is because it doesn't matter if your supplement has it.
Most species that can't absorb D3 through dietary intake are basking species that utilize UVB. Those species absorb the required D3 to help metabolize their dietary calcium and phosphorus via the rays they are basking under. (That's why basking species require such good UVB lighting in their captive enclosures. D3 is utilized in the metabolism of calcium and phosphorus. Without the appropriate lighting, their bodies can't absorb the needed calcium and phosphorus from the food they consume.) Leopard Geckos are nocturnal, so they don't have the high UVB exposure that the basking species do.
This is why you will see information about using it, and not using it. There is no clear line when dealing with Leopard Geckos.
If you can't get a supplement that doesn't contain D3, then use one that does. The goal however is to keep a dish in their at all times.
There are supplements out there that don't contain D3. I know this for fact because I use them. lol A great calcium supplement is the Rep-Cal with No D3 - No Phosphorus (Green Label). The Herptivite I also suggest is also manufactured by Rep-Cal.
Here is a link to their website:
Rep-Cal
You can ask all the questions you like on this site pertaining to your Leo. People refer everyone to the caresheet because more than 98% of all questions asked about Leopard Geckos is covered in there.
I will try to find some time to update that caresheet seeing as you didn't find that section clear.
I hope this response has helped you.