Inositol is a vitamin-like substance whose core function is to serve as a biosynthetic precursor of phosphatidylinositol and very-low-density lipoprotein (VLDL), promoting fat transport and metabolism in the liver and effectively preventing fatty liver—this is especially critical in high-yielding laying hens, rapidly fattening meat poultry, and finishing pigs; meanwhile, the inositol trisphosphate (IP₃) produced after its phosphorylation is an important intracellular second messenger involved in signaling regulation such as hormone response, neural transmission, and cell differentiation. In aquaculture feed, inositol also plays a key role in osmoregulation, helping fish, shrimp, and crabs maintain fluid balance under stress conditions such as salinity fluctuations and water changes, and significantly promoting molting, metamorphosis, and survival of crustacean larvae. In addition, by maintaining the integrity of the phospholipid bilayer of cell membranes, it works synergistically with the glutathione system to exert antioxidant effects, reducing cortisol and improving immune indicators under heat stress and high-density farming conditions; it is an easily overlooked yet highly cost-effective functional additive in scenarios with a high incidence of fatty liver and in aquatic seedling feed.