Repti Calcium without D3 is an ultra fine precipitated calcium carbonate supplement. It is a phosphorus-free calcium supplement for reptiles and amphibians. It has a unique shape/high surface area per gram resulting in increased calcium bioavailability. Repti Calcium without D3 is a highly bioavailable source of calcium carbonate and is free of harmful impurities (not from Oyster Shells). It has safe levels of vitamin D3. Use Repti Calcium without D3 with reptiles that are able to meet their vitamin D3 levels.