Calcium D-saccharate tetrahydrate is primarily used in the pharmaceutical industry as an excipient in drug formulations. It acts as a stabilizer and bulking agent, ensuring the consistency and effectiveness of medications, particularly in tablet and capsule forms. Additionally, it is utilized in the food industry as a calcium supplement, enhancing the nutritional value of various products. Its ability to bind with other compounds makes it useful in purification processes, such as refining sugars and other substances. In research, it serves as a reagent for studying calcium-related biochemical pathways.