Deliberations and evaluations of the approaches, endpoints and paradigms for dietary recommendations of the other trace elements.

Circumstantial evidence suggests that aluminum, arsenic, bromine, cadmium, germanium, lead, lithium, nickel, rubidium, silicon, tin and vanadium are essential. The evidence is most compelling for arsenic, nickel, silicon and vanadium. The estimated daily dietary intakes for these elements are arsenic, 12-50 micrograms; nickel, 100 micrograms; silicon, 20-50 mg and vanadium, 10-20 micrograms. By extrapolation from animal studies, the daily dietary intakes of these elements needed to prevent deficiency or to provide beneficial action in humans are arsenic, 12-25 micrograms; nickel, 100 micrograms; silicon, 2-5 mg (based on 10% bioavailability in natural diets) and vanadium, 10 micrograms. Thus, the postulated need by humans for these elements can be met by typical diets. Because there may be situations, however, where dietary intake does not meet the postulated requirements, research is needed to derive status indicators in humans and to further study the relationships of low intake or impaired bioavailability of these ultratrace elements to various diseases.