Zinc also plays a role in the regulation of appetite, stress level, taste, and smell. It is essential for normal growth and development, and for most aspects of reproduction in both males and females.

Zinc is frequently deficient in people with HIV, even in those with still-high CD4 counts. It has been shown that there is a progressive decrease in blood levels of zinc that correlates with disease severity: Zinc is needed for the proper production of immune cells, and for T-cell differentiation and maturation, making it essential for preservation of cell-mediated immunity. Zinc also inhibits the action of tumor necrosis factor, increases of which are common causes of HIV activation, fevers, and wasting.

For all these reasons, replenishment is crucial, and studies in people with HIV have shown increases in T cell counts when deficiencies were reversed with supplementation.

Symptoms of zinc deficiency include: loss of appetite, poor growth, weight loss, impaired taste or smell, poor wound healing, skin abnormalities (such as acne, atopic dermatitis and psoriasis), hair loss, lack of menstrual period, night blindness, hypogonadism and delayed sexual maturation, white spots on the fingernails and feelings of depression.

Returning zinc levels to normal also seems to improve wound healing and prevent the abnormal scarring sometimes seen in those who are deficient. Zinc supplementation can also help to reverse taste and smell problems and the appetite loss that they can create. There have also been anecdotal reports that zinc supplementation helps to restore normal sex drive, not surprising since levels of testosterone drop when zinc deficiency is present, and adequate levels of testosterone are necessary for maintenance of sex drive.

Be careful to balance long-term zinc supplementation with a sufficient supplementation of copper because they compete for absorption. Copper usually loses when they compete and the result can be a copper deficiency.

Researchers have suggested that zinc supplementation might improve some of the immune defects of HIV infection, inhibit disease progression, and enhance resistance against opportunistic infections, and several studies have supported this.

There are many anecdotal reports that zinc supplementation (usually in combination with vitamin A, essential fatty acids, and B vitamins) often results in improvement in various skin problems, including rashes and dry, itchy skin.

Copper and zinc supplements should be taken at different meals because they compete for absorption. Zinc taken long-term without sufficient copper to balance it can drive too much copper out of the body and can result in both heart problems and immune dysfunction. Most experts in the field recommend an intake of zinc to copper in a ratio of 10:1.  In other words, if you take 50 mg of zinc per day, take 5 mg of copper.

Common side effects include: stomach upset, nausea, vomiting, and a metallic taste in the mouth.

Possible interactions: People using ACE inhibitors (used for high blood pressure), antibiotics (namely oral quinolones), immunosuppressants, NSAIDs, and those on HRT (hormone replacement therapy) should not use zinc before consulting their doctor.