A Rare Pure Calcite Urolithiasis Confirmed by Infrared Spectroscopy

This case report describes a 41-year-old woman with no significant medical history and a normal body mass index (BMI), who presented with ureterohydronephrosis due to a 5.5mm x 9mm calculus composed primarily of calcite (CaCO₃) at the ureterovesical junction. The kidney stone, associated with cystitis and perirenal fat infiltration, was spontaneously expelled and subsequently analyzed. Optical microscopy revealed a grey homogeneous stone with a rough surface and white crystals upon examination. Fourier-transform infrared spectroscopy (FTIR-ATR) confirmed the stone's composition as pure calcite, displaying characteristic absorption bands indicative of its crystalline structure. The patient reported long-term use of multiple vitamins and plant-based supplements, possibly contributing to stone formation. The discussion includes insights on calcite urolithiasis, highlighting factors such as alkaline urine pH and calcium metabolism that can influence stone formation, underscoring the complexity of managing kidney stone risk in supplement users.