Importance for health

Immune system

Zinc plays an important role in cellular processes, such as the humoral and cell-mediated immune defense. The normal activity of special immune cells and biological activity in a series of lymphokines can only be maintained when Zinc is present in effective concentrations. Some studies have demonstrated a relationship between Zinc intake and reduction in the length and severity of a cold. For example, Prasad et al. showed that symptoms only lasted 4.5 days in a group of 48 persons taking about 24 mg zinc daily for a 12-day period compared to 8.1 days in the control group.

Skin health

The process of wound healing consists of various stages of tissue reconstruction. During the inflammatory process, special immune cells remove bacteria from the wound and further cells are needed in the growth of new tissue. Zinc is thought to have a beneficial role in new cell formation.

Bone health

Zinc is contained in crystals forming bone matrix and is required to stimulate bone formation and inhibit bone decomposition. It is probable that zinc, in combination with calcium, has a positive influence on osteoporosis risk.

This is particularly the case for growing children due to Zinc’s importance in “peak-bone-mass”. For elderly women, particularly those affected by osteoporosis, who have lower serum zinc levels and higher urinary excretion rates, this relationship is also particularly important. For example, a Swedish study has shown that low phosphorus and zinc intakes in middle-aged and elderly men showed increased fracture risk.

Due to poorly balanced diets and worse absorption, the risk of deficiency increases in the elderly; in the USA 75% of people aged 60-90 years did not meet dietary Zinc recommendations. In Europe about 414,000 hip and 1,400,000 vertebral (spinal) fractures are estimated to occur each year.

Eye health

760 per 100,000 people in Europe suffer from visual impairment. The results of research into the role of Zinc in age-related macular degeneration (AMD) and dark adaptation have been inconclusive. It is known for certain, however, that the retina contains a high concentration of Zinc compared to other human tissues, which assists the normal functioning of the retina. Furthermore, it seems likely Zinc plays a role in the phototransduction process, so that deficiency may result in night-blindness and poor dark adaptation. The apparent positive influence of Zinc on AMD may be explained by the lower Zinc concentration in the retinal pigment epithelium in persons affected by AMD.

In the AREDS report, the relation between high dose intake of antioxidants or Zinc (80 mg) or a combination of both on AMD and visual acuity was examined in 3640 persons for 6.3 years. The positive effect of visual acuity was only statistically significant in the group treated with Zinc and antioxidants. After treatment a risk reduction for AMD of 17% compared to placebo was noted for antioxidants, and 21% for those taking Zinc. The greatest risk reduction, about 25% was associated with subjects taking antioxidants and Zinc. Therefore a combination of Zinc and antioxidants might be an effective treatment in severe AMD.