Your immune system plays a central role in maintaining your health, helping to fight infections, as well as prevent potentially infectious agents from entering your system. Damage to your immune system leaves you open to infection, so that even relatively mild disorders, like a cold or the flu, can prove very dangerous. A number of chemicals -- including several vitamins -- play a number of roles in maintaining a healthy immune system.
Components of Immune System
Your immune system is made up of a number of tissues that work together to fight infection. Your integumentary system -- including your skin and hair follicles -- forms a primary barrier against infectious agents, preventing these microbes from entering your body and gaining access to your internal tissues. Your white blood cells form a secondary defense, capable of targeting and destroying microbes that do enter your system, as well as promoting inflammation to fight the infection. Finally, the spleen helps to generate and house white blood cells, while lymph nodes and vessels can transport immune cells to a region of infection to help fight disease.
Vitamin A
Consuming vitamin A helps to maintain your immune system. Retinol, a biologically active form of vitamin A, helps to form healthy skin and regulates skin cell growth, helping to maintain an effective barrier to prevent infection. In addition, vitamin A in your body contributes to the maturation of new white blood cells, and therefore also aids in the destruction of infectious particles that do enter the body.
VItamin C
Vitamin C also contributes to a healthy and effective immune system. Like vitamin A, vitamin C helps maintain your skin to form a barrier against infection. Vitamin C in your body contributes to collagen formation, which in turn helps your body to produce new skin tissue after injury. By promoting proper healing, vitamin C helps to repair any wounds that would otherwise serve as entry points for infectious bacteria, viruses or fungi.
Vitamin D
Vitamin D in your system can also contribute to a healthy and effective immune system. One form of vitamin D, called 1,25-dihydroxyvitamin D helps to regulate your immune function. The vitamin might contribute to innate immunity -- your ability to fight off new infections -- while also protecting against over-activation of your immune system that can cause disease, according to the Linus Pauling Institute at Oregon State University. As a result, vitamin D might help to prevent auto-immune disorders.
