Vitamin A (VitA) is a micronutrient that is crucial for maintaining vision, supporting growth and development, and preserving the integrity of epithelial and mucus membranes. Vitamin A is known as an anti-inflammatory vitamin due to its critical role in enhancing immune function. It plays a role in the development of the immune system and takes on regulatory roles in cellular immune responses and humoral immune processes. Additionally, it is known that Vitamin A has a therapeutic effect in the treatment of various infectious diseases. This review aims to better understand the relationship between nutrition and the immune system by reviewing recent literature related to Vitamin A in immunology and briefly introducing clinical applications of VitA in the treatment of various infectious diseases. However, there has not been sufficient research on the mechanisms by which Vitamin A affects immune function at the molecular level. At the clinical and community levels, nutrition research would greatly benefit from developing a method that can simply measure Vitamin A status and is not adversely affected by the Acute Phase Response (APR). Increasing these studies will enhance our understanding of how Vitamin A impacts the infection-malnutrition cycle and will strengthen the efforts of the international health community to eliminate Vitamin A deficiency.