FIGURE 12-1 The relationship between endogenous zinc excretion and absorbed zinc. Heavy line represents the linear regression of intestinal excretion of endogenous zinc (mg/day) versus absorbed zinc (mg/day) from means of ten data sets for healthy men ages 19 through 50 years. The bold dashed lines above and parallel to the regression line represent the total endogenous zinc losses for men and women in relation to zinc absorption. The faint dashed line is the line of perfect agreement or equality of endogenous zinc and absorbed zinc. The intersect of this line with that of total endogenous zinc excretion indicates the average minimum quantity of absorbed zinc necessary to match endogenous losses for men and women. SOURCE: Hunt JR et al. (1992), Jackson et al. (1984), Lee et al. (1993), Taylor et al. (1991), Turnlund et al. (1984, 1986), Wada et al. (1985).
Physical Growth Response to Zinc Supplementation
In contrast to studies on the effects of low-dose zinc supplements on clinical features (e.g., pneumonia, diarrhea [Bhutta et al., 1999]) and on nonspecific laboratory functional tests of zinc status (e.g., tests of neuro-cognitive function [Sandstead et al., 1998]) or immune status (Shankar and Prasad, 1998), studies of the effects of zinc supplementation on physical growth velocity in children are useful in evaluating dietary zinc requirements for several reasons.