Review of Various Indicators for Assessment of Zinc Requirement and Effectiveness
Zinc (Zn) has been shown to be an essential micronutrient for all organisms including plants, animals and human beings. Deprivation of zinc arrests growth and development and produces multiple system dysfunctions in all these organisms. Because of the involvement of this micronutrient in so many core areas of metabolism, it is common that the features of zinc deficiency in humans are nonspecific with a wide range including growth retardation, alopecia, diarrhea, delayed sexual maturation and impotence, eye and skin lesions and even impaired appetite. Clinical features and laboratory criteria are not always consistent. This inconsistency poses a major difficulty in the search to reliable yet sensitive clinical or functional indicator of zinc status for validation. Further, it has become clear now that the homeostatic mechanisms fall short of perfection and clinically important features of zinc deficiency can occur with only modest degrees of zinc deficiency. In this review article we try to look critically at the available tests and various indicators for assessment of zinc’s level for potential requirement and effectiveness and try to conclude about the efficacy of each.