Zinc is an essential nutrient with many roles in the human body. It is needed for enzyme activity and the immune systems. It has anti-inflammatory properties and is also required for the sense of taste and smell.
A deficiency in zinc can therefore adversely affect immune function, and increase the risk of infections in the following ways;
- impairing the formation, activation and maturation of lymphocytes
- decreases the ratios of helper and suppressor T cells
- decreases the production of interleukin-2, and the activity of natural killer cells and cytotoxic t cells
- elevation of pro-inflammatory mediators.
The result of this is an increase in the risk of infections like upper respiratory track infections and inflammatory diseases.
Zinc is found naturally in many foods, including oysters, crab, lobster, beef, pork, poultry, beans, nuts, whole grains, and dairy products. Supplementation is fairly safe, up to levels of 40mg/day. Chronic high doses can cause some gastro intensitinal problems, as well as lowered copper status, reduced immune function, and reduced levels of high-density lipoproteins (HDL).
Zn lozenges <75mg, rather than tablet form, have also been shown to be more effective in aiding in improved immunity, reducing infections and duration, when taken within 24 hours of the onset of symptoms for the duration of the sickness.