What nutrient is essential for immune function and can be found in citrus fruits?

Vitamin C plays a crucial role in immune function, serving as an antioxidant that protects cells from damage caused by free radicals. It is essential for the growth and repair of tissues throughout the body and is important for the production of collagen, a protein necessary for the skin, cartilage, tendons, ligaments, and blood vessels. Moreover, vitamin C enhances the function of immune cells, helps the body absorb iron from plant-based foods, and has been shown to reduce the duration and severity of colds.

Citrus fruits, such as oranges, lemons, and grapefruits, are particularly rich sources of vitamin C, making them a go-to option for supporting immune health. Including these fruits in your diet can help meet the body's vitamin C needs and promote overall well-being.

Other options, while important for various aspects of health, do not have the same direct association with immune function as vitamin C. Vitamin A is significant for maintaining vision and skin health, vitamin B6 is necessary for protein metabolism and cognitive development, and vitamin D plays a key role in bone health and calcium regulation. However, none of these nutrients provide the same level of support for immune cells as vitamin C does.