The Exo Terra Calcium Powder Supplement 3.2 oz is a phosphorus-free calcium powder that provides essential calcium for reptiles and amphibians. Calcium deficiency is a common issue in captivity, and this ultra-fine supplement contains high levels of calcium to support strong bones and prevent metabolic bone disease. Simply dust insects or mix with food – its low-phosphorus, vitamin-free formula ensures proper calcium metabolism when used with a multivitamin.