Zinc is an important player in immune system functioning, but this doesn't necessarily mean that zinc supplementation can improve your immune health if you aren't deficient. Most people in the United States have sufficient zinc intake, so zinc supplementation is generally unwarranted for them. Understanding the role of zinc in immune health can help you decide whether to increase your zinc intake. Before supplementing with zinc, however, you should talk to a doctor about your zinc status and whether you need extra zinc.
Zinc
The essential nutrient zinc plays a role in many different bodily functions, including DNA synthesis, wound healing, cell division and immune function. Zinc must be obtained through diet and must be consumed on a regular basis, because the body cannot create it or store it for later use. Adult women need 8 mg of zinc a day and adult men need 11 mg daily. Red meat and poultry are common sources, but many other foods contain zinc as well, including oysters, beans, whole grains and fortified cereals.
Immune System
The immune system is made up of many components, including the specialized tissues that protect the body from disease and the cells that recognize and destroy invading organisms. The two main cells of the immune system are the phagocytes and lymphocytes. Phagocytes are the cells that engulf and chew up bacteria and fungi. Lymphocytes include the B cells, which identify invaders and produce antibodies against them, and the T cells, which destroy invaders tagged with antibodies. Another part of the immune is complement, a group of proteins that help kill bacteria, viruses and infected cells.
Zinc Deficiencies
Zinc deficiencies can depress the immune system. Because zinc is needed to activate T cells, a lack of this nutrient can cause problems with this aspect of immunity. A lack of zinc also affects the functioning of B cells, phagocytes and complement. Low levels of zinc have been associated with higher instances of pneumonia in elderly individuals and childhood infections, according to the Office of Dietary Supplements. Zinc also operates in more than 300 organs and tissues that have a secondary effect on immune function, so its impact on immunity can be difficult to quantify, according to a 2000 report in the "Proceedings of the Nutrition Society."
Boosting Immunity with Zinc
In cases of zinc deficiency or insufficiency, supplementation with zinc may improve immune functioning. A 1998 study in the "Journal of the American Geriatric Society" showed that zinc supplementation byelderly individuals, a population with historically low levels of zinc, raised levels of immune cells. However, adding zinc to the diet when levels are already at acceptable levels might not have an impact on immune function. In fact, excess zinc, in doses of 150 mg to 450 mg of zinc per day, might actually reduce immune function, according to the Office of Dietary Supplements. So, supplementation could have a detrimental effect on your immunity.
References
- Office of Dietary Supplements: Zinc
- Linus Pauling Institute at Oregon State University: Zinc
- "Proceedings of the Nutrition Society"; Zinc and the Immune System; L. Rink, P. Gabriel; November 2000
- KidsHealth; The Immune System; Steven Dowshen; November 2009
- "Journal of the American Geriatric Society"; The Effect of Zinc and Vitamin A Supplementation on Immune Response in an Older Population;C Fortes, et al.; January 1998
