The vitamin most commonly associated with enhancing the immune system is vitamin C. It plays a crucial role in supporting the immune response by promoting the production of white blood cells and acting as a powerful antioxidant. Vitamin C helps protect the body from oxidative stress and supports skin health, contributing to the first line of defense against pathogens. While it can be obtained from various fruits and vegetables, such as citrus fruits, strawberries, and bell peppers, some individuals may benefit from supplementation to meet daily requirements.