Complex sentence: The treatment of hypoparathyroidism is limited by the fact that there is no artificial form of the hormone that can be administered as replacement; calcium replacement or vitamin D can ameliorate the symptoms but can increase the risk of kidney stones and chronic kidney disease.
Split into simpler sentences: The treatment of hypoparathyroidism is limited by the fact that there is no exact form of the hormone that can be administered as replacement. Calcium replacement or vitamin D can ameliorate the symptoms but can increase the risk of kidney stones and chronic kidney disease.