ZINC AND ITS MEDICAL RELEVANCE

Zinc is an essential trace element element found in humans. It is one of the transition metals found in the periodic table. Zinc is found in the muscle (65% content). However ,higher concentrations are found in the integumental tissues (i.e skin, hair and nails),the retina and the male reproductive organs. The average adult body contains between 10-15mg of zinc.



Richest sources of dietary zinc include whole grains(germs),seeds, nuts, eggs and leafy vegetables, shellfish, dairy products. Zinc is not really stored and is readily lost from the body through faeces, sweating, urine, menstruation. During tissue metabolism and repair, the amount of zinc excreted is greatly increased.




Zinc plays essential role in DNA synthesis and cell division, a constituent of many dehydrogenase enzymes, erythrocyte carbonic anhydrase (essential for acid-base balance).anti-oxidant enzymes such as superoxide dismutase (SOD) which mops up free reactive oxygen species that are cell destructive. Zinc is involved in the binding of insulin within the beta cells of Islets of Langerhans, necessary for male reproductive functions and spermatogenesis especially in the production of testosterone by the Leydig cells. Collagen synthesis and degradation is facilitated by collaginase, a zinc-dependent enzyme.




Zinc deficiency can result in thymic atrophy. Studies have also revealed that symptoms of growth retardation, skin lesions and impaired sexual development was observed in adolescent malnourished boys in Iran and Egypt and was traced to their consumption of phytate bread. Acrodermatitis enteroparthica with symptoms of severe skin lesions, diarrhea ,loss of hair (alopedica) and mental disturbances result from zinc deficiency.




Research has shown that zinc plays a significant role in skin and connective tissue metabolism. The Greeks used Calamine solution on the skin to treat disorders. Zinc, usually in the form of insoluble zinc oxide has been used as skin ointment in topical applications to treat a variety of dermatological disorders. Treatment of surgical patients daily with oral doses of 50mg zinc (as Zinc sulphate) has been shown to enhance wound healing. Chronic ulcers have been healed successfully by the use of oral Zinc sulphate which led to the increase of zinc plasma concentration to between 30-45µmole/L.