Found in fresh oysters, herring, wheat germ, pumpkin seeds, milk, steamed crab, lobster, chicken, pork chops, turkey, lean ground beef, liver, eggs.

One of the most important nutrients for a healthy immune system, zinc is a vital ingredient in a number of enzymes essential to the immune response. Zinc has been shown to increase the activity of natural killer cells and to boost the production of antibodies in response to infections. It can also hasten wound healing and may have some antiviral properties. Lozenges containing zinc as the active ingredient may be useful in shorting the duration of colds. Research has suggested that zinc may be beneficial for patients with macular degeneration. As zinc is required for the production of the antioxidant enzyme superoxide dismutase, which neutralises potentially damaging free radicals, it may help to fight cancer. The mineral also aids in the production of testosterone and boosts sperm production.

Symptoms of zinc deficiency include fingernails with white spots or bands or an opaquely white appearance, loss of taste, smell and appetite, delayed sexual development in adolescence, underdeveloped penis and less full beard and underarm hair in boys, irregular menstrual cycle in girls, infertility and impaired sexual function in adults, poor wound healing, loss of hair, increased susceptibility to infection, reduced salivation, skin lesions, stretch marks, reduced absorption of nutrients, impaired development of bones, muscles and nervous system, deformed offspring, and dwarfism.

30-50mg (take with copper to yield a zinc to copper ratio of 10:1). RDA is 15mg for men and 12mg for women. Coffee drinkers should take zinc supplements at least one hour before or two hours after drinking coffee, as it reduces the body’s ability to absorb zinc by 50%.

The maximum safe level for long-term use is 15mg, for short-term use, 50mg can be taken safely. Supplementation at levels greater than 80 mg/day may suppress immunity and cause other side effects.

High doses of zinc affect the absorption of iron and copper. Zinc should be taken with food to avoid irritating the stomach. People with liver damage or an intestinal disorder should consult their doctor before taking supplementary zinc. Results of several studies conducted over the last few years have linked zinc to Alzheimer’s disease. However, one study found that the zinc appeared to improve mental performance in Alzheimer’s patients. Until the effect of zinc on Alzheimer’s is understood more clearly, people diagnosed with Alzheimer’s and those deemed at high risk of developing the disease may wish to avoid taking supplementary zinc.

SOLUBILITY: Insoluble in water