http://webspinners.com/coloherp/cb-news/Vol-28/cbn-0111/AskVet.html
In reptiles it is called acute hypercalcemia from acute vitamin D3 overdose this can result in calcification of the kidneys.
Also here is more info: http://www.anapsid.org/uvd3.html
Linda Randall, DVM, ABVP: Is it possible to overdose a herp on calcium?
I have never been able to overdose a reptile with just calcium, nor have I spoken to a veterinarian who has. Reptiles are able to regulate the amount of calcium their body absorbs, and the rest is excreted in the feces. The problem begins when Vitamin D is added to the calcium mixture. This vitamin encourages the reptiles system to absorb excessive calcium, which eventually leads to hypercalcemia, a serious condition. The calcium to phosphorus ratio is also very important when looking at calcium levels in the food offered to reptiles, and when reading blood chemistry results. If you have a herp that requires calcium supplementation, make sure it is only calcium that you are using. (At our hospital we use calcium carbonate, which is inexpensive and comes in a fine powder.) For anything else, consult with your veterinarian first to ensure you are feeding your particular pet correctly. When you read labels, you will find that many of the products sold as calcium supplements have Vitamin D3 added. This is not necessarily a bonus!
In reptiles it is called acute hypercalcemia from acute vitamin D3 overdose this can result in calcification of the kidneys.
Also here is more info: http://www.anapsid.org/uvd3.html

You asked for it. You pushed and pushed and finally Dan cited his credentials and his history. Maybe that will teach you not to ask a question to which do not already know the answer.