ZINC

Overview

CAS number
7440-66-6
Functional Class
Food Contaminant
METALS

Evaluations

Evaluation year: 1982

Comments:
Zinc is an essential element in the nutrition of man and animals. Studies with experimental animals have shown that high levels of dietary zinc can cause anaemia as well as decreased levels of copper and iron absorption, and reduction in the activities of several important enzymes in various tissues. These effects also occur at lower levels of dietary zinc when the diet is deficient in copper. Zinc was not teratogenic, had no effect on the reproductive performance of test animals, & was not mutagenic in a number of bacterial and mammalian systems. The required daily intake for adult humans is about 15 mg/day. The average dietary zinc intake in adults is 14-20 mg/day and is thus sufficient for nutritional needs. There is a wide margin between nutritionally required amounts of zinc and toxic levels. Clinical studies in which up to 600 mg of zinc sulfate (equivalent to 200 mg elemental zinc) has been administered daily in divided doses for a period of several months is the basis for the PMTDI for Zn of 0.3-1.0 mg/kg bw/d.
Intake:
average dietary zinc intake in adults is 14-20 mg/day
Tolerable Intake:
PMTDI 0.3-1 mg/kg bw/d
Meeting:
26
Report: 
TRS 683-JECFA 26/32
Tox Monograph: 
FAS 17-JECFA 26/320

Toxicological study

Pivotal Study:
Brewer et al., 1967: Fourteen patients suffering from decubitus ulcers were given either 600 mg/day (divided into 3 doses) of zinc sulfate or a lactose placebo for 4 months. No evidence of toxicity. Carruthers, 1969; Cohen, 1969, Husain, 1969: 2 groups of 52 patients with ulcers were given 660 mg/day of lactose or 660 mg of zinc sulfate/day for 10 weeks. Mild diarrhoea in 3 patients was the only toxic effect noted. Other studies with patients who were treated with doses of zinc sulfate (440 to 660 mg/day) for bedsores or leg sores also failed to demonstrate any toxicity. Serjeant et al., 1970: 16 males and 18 females suffering from sickle cell anaemia were treated 3 times daily with either 220 mg of lactose (placebo) or 220 mg of zinc sulfate for 6 months. No symptoms of toxicity were associated with the dosage used in this study
Animal Specie:
Human
Effect:
No significant adverse effects
NOAEL:
220-600 mg/d zinc sulfate
PMTDI:
0.3-1 mg/kg bw/d
Point of departure:
220-600 mg/d zinc sulfate
Previous Years:
1966, NMRS 43/TRS 373-JECFA 10/17
1966, NMRS 43/TRS 373-JECFA 10/17