The importance of zinc for humans has long been recognized. Deficiency of zinc in humans is attributed to the nutritional factors and various disease states. High phytate content of cereal proteins can decrease the availability of zinc, increasing the incidence of zinc deficiency in the population surviving on cereal proteins mostly. Zinc deficiency has been observed in patients with malabsorption syndrome, cirrhosis of the liver, chronic renal disease, sickle cell disease and other chronically debilitating diseases. Few manifestations of chronically zinc-deficient individuals are growth retardation, skin changes, male hypogonadism, mental lethargy, poor appetite and delayed wound healing.

Dermatological manifestations, such as diarrhea, mental disturbances, alopecia and intercurrent infections can predominate in severely zinc-deficient patients. If left untreated, the condition can become fatal. Zinc deficiency can affect the testicular functions adversely in humans and animals. Zinc is essential for spermatogenesis and is involved in several biochemical functions. Numerous zinc metalloenzymes have been documented in the past. Zinc is necessary for each step of cell cycle in microorganisms and for DNA synthesis. The effect of zinc on protein synthesis can be attributed to its vital role in metabolism of nucleic acid. The activities of many zinc-dependent enzymes are shown to be adversely affected in zinc-deficient tissues. Also, zinc has a role in stabilization of biomembrane structure and polynucleotide confirmation.

Source: Prasad AS. Clinical and biochemical manifestation zinc deficiency in human subjects. J Pharmacol. 1985;16(4):344-352.