The immune system consists of a network of cells, tissues and organs working within your body to protect you from a host of harmful organisms, such as bacteria and viruses. Maintenance of a healthy immune system involves good self-care habits and a balanced diet rich in nutrients, such as vitamins. The essential vitamins work together to keep you healthy, and vitamins with antioxidant activity play a significant role in strengthening your immune system.
Antioxidant Vitamins
Antioxidants are substances that protect your cells from damage caused by free radicals. When your body breaks food down, oxygenation -- or oxygen entering your cells -- occurs, and this natural process forms byproduct compounds that roam freely to different cells and organs. Free radicals also form when you ingest pollutants from the environment or toxins from foods. The free-radical compounds cause cellular harm and inflammation if you do not have enough antioxidants to neutralize them and prevent damage. Vitamins A, C and E function as antioxidants to protect and strengthen your immune system.
Vitamin A
Vitamin A plays a role in strengthening your immune system by aiding in the creation of white blood cells, which destroy invading viruses or bacteria. Vitamin A also protects your eyes, intestines, urinary tract and respiratory system. You can get all of the vitamin A you need each day from food, including carrots, spinach, sweet potatoes, mangoes or dairy. The daily recommended allowance for adults is 700 to 900 mcg. If you take a vitamin A supplement, do not exceed 3,000 mcg per day for risk of toxicity, including liver abnormality or nervous system disorders, notes the Office of Dietary Supplements.
Vitamin C
Vitamin C stimulates the production and function of neutrophils, a type of white blood cell that destroys bacteria. This vitamin protects healthy immune cells through antioxidant activity and is also required for building new collagen for your tendons and blood vessels. The daily recommended allowance of vitamin C for adults is 75 to 90 mg, with an upper limit not to exceed 2,000 mg. Food sources include citrus fruits, broccoli and berries. Exceeding the upper limit of vitamin C through use of supplements is not known to cause toxicity, notes the Linus Pauling Institute. However, consult your physician before using supplements in high doses.
Vitamin E
Vitamin E is an antioxidant that prevents the formation of reactive oxygen molecules, which permit free-radical damage. Vitamin E is also involved in regulating immune system function, but research is ongoing to determine the exact effect of this vitamin on the immune system, notes MayoClinic.com. Dietary sources include eggs, leafy green vegetables, vegetable oil and nuts. The daily recommended intake of vitamin E for adults is 15 mg, with an upper limit of 1,000 mg. High-dose use of vitamin E supplements can cause hemorrhage, and consultation with your physician is suggested before taking supplements.
Additional Tips
All of the essential vitamins, including the B group and vitamin D, play a role in protecting your health. A well-balanced diet with fruits, vegetables, whole grains, lean meats and low-fat dairy can help you get your daily vitamin intake. The healthier you eat, the more defenses you give your body for fighting off infections. Consult your physician before taking vitamin supplements to boost your immune system.
