A Comprehensive View on Oxidative Mechanisms of Vitamin A and Its Implications for Effective Formulation Strategies in Food Systems

Abstract

Vitamin A is an essential fat-soluble micronutrient widely used in food and feed sectors to combat deficiency symptoms worldwide and meet nutritional needs, yet its intrinsic oxidative instability continues to challenge product design and shelf-life. Although various delivery strategies, ranging from bulk oils to advanced encapsulation systems, have been employed, its degradation remains difficult to predict. Vitamin A is susceptible to oxygen mediated oxidation, forming epoxides, cleavage products, hydrolysis derivatives, and dimers through mechanisms influenced by environmental factors (light, heat, etc.), matrix composition, and molecular structure. While antioxidants can provide protection, their performance is highly system-dependent, and some compounds may even become pro-oxidant under certain conditions. The design of stable vitamin A formulations is hindered by an incomplete understanding of the fundamental oxidative processes. Most existing studies emphasize radical-driven propagation steps, but emerging evidence suggests that earlier, perhaps non-radical activation events, such as triplet-state excitation and electron-transfer processes leading to reactive species, may play a critical role in initiating degradation. Furthermore, the microstructural organization of formulations, molecular interactions within encapsulating systems, and the potential involvement of concerted pathways have been largely overlooked. These factors may significantly modulate vitamin A reactivity by altering molecular environments and influencing activation energy. A deeper mechanistic understanding of these oxidative initiation processes is therefore essential. Such knowledge would enable the design of next-generation formulations that stabilize vitamin A at its ground state, improving efficacy, safety, and long-term nutritional value.

Practical Applications: A better understanding of how vitamin A degrades has direct practical value for the food and feed industries. By identifying not only its links to well-known radical oxidation pathways but also its early-stage activation mechanisms, manufacturers can design more effective stabilization strategies, either by improving encapsulation systems or by selecting antioxidants that remain protective rather than becoming pro-oxidant under certain conditions. Additionally, insights into how formulation structure and ingredient interactions influence vitamin A degradation can guide the development of optimized delivery matrices, such as emulsions or microcapsules, tailored to specific products. Applying this knowledge helps extend shelf life, maintain nutritional value, and reduce economic losses due to degradation. It also supports the creation of safer, more reliable fortified foods, ensuring that populations at risk of deficiency receive consistent and effective vitamin A intake over time.