DIETARY STANDARDS FOR MANGANESE - OVERLAP BETWEEN NUTRITIONAL AND TOXICOLOGICAL STUDIES

The Estimated Safe and Adequate Daily Dietary Intake (ESADDI) for adul ts for manganese is 2-5 mg Mn/d, The LOAEL (lowest-observable-adverse- effect level) for manganese in water is 0.06 mg Mn/(kg.d) or 4.2 mg Mn /d for a 70-kg individual. The inconsistency in these standards reflec ts limitations in the available data as well as differences in the way in which the standards are calculated, Manganese balance and excretio n data are not useful biomarkers of manganese exposure but do demonstr ate that the body is protected against manganese toxicity primarily by low absorption and/or rapid presystemic elimination of manganese by t he liver. Serum manganese concentrations in combination with lymphocyt e manganese-dependent superoxide dismutase (MnSOD) activity, and perha ps blood arginase activity, seem to be the best way to monitor ingesti on of insufficient manganese, Serum manganese concentrations in combin ation with brain magnetic resonance imaging (MRI) scans, and perhaps a battery of neurofunctional tests, seem to be the best way to monitor excessive exposure to manganese.