Calcium deficiency is a major dietary problem in captive reptiles. Exo Terra Calcium + D3 Powder Supplement contains high levels of phosphorus-free calcium as well as balanced amounts of vitamin D3 for optimal calcium absorption and to help ensure long-term health. Vitamin D3 aids in the proper absorption of calcium and is vital for captive reptiles not exposed to natural sunlight or ultraviolet lights. Exo Terra Calcium + D3 Powder Supplement is a complementary food for reptiles. Contains the essential elements for proper calcium metabolism Phosphorus free Ultra fine powder For reptiles