The First Observation of Calcium Oxalate Accumulation in Human Hair

This study reports the first detection of calcium oxalate in the medulla of human hair, found in 11% of samples from the general population using synchrotron FTIR microspectroscopy. Calcium oxalate was primarily located within or near the hair medulla and was identified in its monohydrate form (COM). The origin of COM in hair is unknown but may be linked to secondary hyperoxaluria or hair treatments. The findings suggest potential clinical applications for using calcium oxalate in hair as a non-invasive biomarker for managing conditions related to oxalate metabolism, such as kidney stone formation and primary oxaluria.