What is the main role of Vitamin A in immune functions?

Vitamin A plays a crucial role in supporting epithelial regeneration, which is vital for maintaining a healthy immune system. Epithelial tissues, such as those lining the respiratory and digestive tracts, act as barriers against pathogens. Adequate levels of Vitamin A help ensure that these tissues can repair and regenerate properly after injury or infection. This regeneration is essential for the swift recovery of the body's first line of defense against invaders, thereby enhancing overall immune function.

While other functions of Vitamin A, such as its involvement in vision and cell differentiation, are significant, its specific role in epithelial cell turnover and health directly relates to immune defense mechanisms. This emphasis on epithelial health underscores why the support of epithelial regeneration stands out as the main function of Vitamin A in the context of immunity.