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Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc
TABLE 12-6 Requirement for Absorbed Zinc for Adolescent Boys and Girls Aged 14 through 18 Years
Boys
Girls
Intestinal losses
34 μg/kg × 64 kg = 2,176 μg/day
34 μg/kg × 57 kg = 1,938 μg/day
Urinary and integumental losses
14 μg/kg × 64 kg = 896 μg/day
14 μg/kg × 57 kg = 798 μg/day
Semen or menstrual losses
100 μg/day
100 μg/day
Requirement for growth
10 g/day × 20μg/g = 200 μg
5 g/day × 20 μg/g = 100 μg/day
Required absorbed zinc
3,372 μg/day
2,936 μg/day
(see below), the EARs for adolescent boys and girls are calculated to be 8.5 and 7.3 mg/day of zinc, respectively.
Extrapolation from Adults. Based on the extrapolation method described in Chapter 2, the average requirement for adolescent boys and girls is 9.5 and 6.4 mg/day, respectively.
Zinc EAR and RDA Summary, Ages 14 through 18 Years
EAR for Boys
14–18 years
8.5 mg/day of zinc
EAR for Girls
14–18 years
7.3 mg/day of zinc
The RDA for zinc is set by using a CV of 10 percent (see Chapter 1) because information is not available on the standard deviation of the requirement. The RDA is defined as equal to the EAR plus twice the CV to cover the needs of 97 to 98 percent of the individuals in the group (therefore, the zinc RDA is 120 percent of the EAR). The calculated RDA is rounded up to the nearest 1 mg.