D-Xylonic acid calcium salt hydrate is a specialty chemical utilized in biochemical research as a calcium source and buffer in enzymatic assays requiring precise calcium regulation. In pharmaceutical applications, it functions as a supplement with enhanced solubility and bioavailability. Its chelating properties, derived from the xylonic acid ligand, make it suitable for analytical studies involving calcium complexation and metal ion sequestration. The hydrate form supports moisture retention in industrial processes, such as controlled-release drug delivery systems and specialty coatings.