FIGURE 6-1 Range of acceptable copper intakes for the general population.

tion, is rarely observed clinically in the United States. Nonetheless, although nationwide surveys suggest that average intake concentrations within the population are at recommended concentrations, a substantial fraction of the population has intakes below currently recommended concentrations (Table 6-1). The significance of those low intakes remains to be determined.

Some populations are a particular concern:

• Pre-term infants have a lower prenatal accumulation of copper stores and thus can be at increased risk for developing copper deficiency during early infancy.

• Copper deficiency can be induced by select mineral supplements, particularly zinc.

Individuals taking zinc supplements in excess of the Recommended Daily Allowance (RDA) on a chronic basis might be at particular risk.

• Large numbers of the elderly appear to have dietary copper intakes below the recommended copper intake.

• A number of disease conditions, including diabetes and hypertension, are associated with low extrahepatic-tissue copper concentrations.

• Genetic disorders, such as occipital horn syndrome, might confer an increased risk for copper deficiency.

Several groups appear to be at risk for deficiency, but a substantial fraction of the population have intakes at or above the recommended level (Table 6-1). Therefore, the committee does not recommend redressing copper deficiency via the water supply and notes that the MCLG should not be established on the basis of copper deficiency.