We only use the purest calcium carbonate in all our products, which is certified at over 99% no one can beat us when it comes to quality. We purchase direct from the mineral source, keeping a close eye on quality! All calcium carbonate used is food grade. Calcivit also contains a very broad spectrum of vitamins which covers all your reptiles supplemental needs. We have also added 9 different amino acids to aid your reptiles health and calcium absorption!