Gulonic acid is primarily used in the pharmaceutical and food industries. In pharmaceuticals, it serves as an intermediate in the synthesis of ascorbic acid (vitamin C), which is essential for various biological functions and is widely used in dietary supplements and medications. In the food industry, it acts as a precursor for food additives and preservatives, contributing to the stability and shelf life of products. Additionally, it finds applications in biochemical research, particularly in studies related to metabolic pathways and enzyme functions. Its role in these areas highlights its importance in health, nutrition, and scientific advancements.