Zoo Med Repti Calcium is a fanatastic calcium supplement suitable for reptiles and amphibians. Superior to cheaper alternatives, the unique shape and high surface area ensure a high calcium bioavailability. Free of phosphorus and harmful impurities (not from oyster shells), Zoo Med's Repti Calcium is available in a range of sizes and with or without vitamin D3 (without for animals exposed to UV lighting, with for species that are not such as geckos).