The Importance of Zinc in Human Nutrition and Estimation of the Global Prevalence of Zinc Deficiency

This paper summarizes recent research on the importance of zinc for human health, and reviews available methods of evaluating zinc status in individuals and populations. The lack of generally accepted biomarkers of zinc status has impeded estimation of the global prevalence of zinc deficiency. Although measurement of zinc consumption and/or plasma zinc concentration can be used to assess population zinc status, few countries have collected adequate data to permit estimation of the prevalence of zinc deficiency. An alternative method, described herein, is to estimate the zinc content of national food supplies, using FAO food balance sheets; the assumed bioavailability of that zinc based on phytate:zinc molar ratios; and the relation between absorbable zinc and theoretical requirements according to country-specific demographics. The results of these analyses indicate that nearly half of the world's population is at risk for inadequate zinc intake, suggesting that public health programs are urgently needed to control zinc deficiency.