Formulation and stability enhancement using vitamin A encapsulation in ocular abnormalities: A scientific review

The relationship between vitamin A, retinol activity, and eye health has been briefly elucidated. Based on certain reports, vitamin A and retinol activity can help overcome vitamin A insufficiency i.e., xerophthalmia. The present review assesses vitamin A sources, β-carotene and β-cryptoxanthin in vitamin A metabolism, retinol and xerophthalmia, and new application of vitamin A in mitigating xerophthalmia. Vitamin A and its precursors are sensitive, and could lose their biological activity when exposed to light or oxygen. In this context, encapsulation may act as a protection strategy for enhancing vitamin A's biological functions under adverse conditions. With the belief that vitamin A and retinol activity have a long-term association with xerophthalmia, the present review discusses the relationship between vitamin A consumption and its precursors, as well as the physiological effects of vitamin A on xerophthalmia. In conclusion, further research using free and encapsulated forms of vitamin A to prevent vitamin A deficiency and manage xerophthalmia should be emphasised.