Recently it has been reported that the unbalances of food habits and parenteral nutrition etc. induces essential trace elements deficiencies. To clarify essential amounts, toxic amounts and also physiological actions of essential trace elements (zine. copper. manganese. selenium. tin. germanium), the following researchs were studied.
(1) To clarify essential amounts of trace elements for Japanese, trace elements intake were calculated or determined from the results of food survey or determination of trace element amounts in one day foods.
(2) New high-sensitive determination methods of trace elements (selenium. tin. germanium, etc.) in biological samples were established.
(3) New high-sensitive determination method of metallothionein in biological samples by high-performance liquid chromatography were established.
(4) Trace elements deficiencies or over dose intake induced unbalances of other nutrient status, especially, mineral status. For examples, iron deficiency induced other mineral unbalanced, copper deficiency induced iron deficiency, protein deficiency enforced selenium deficiency and rats fed over dose germanium decreased serum potassium concentration and increased serum TG or phospholipid concentration, etc. Manganese deficient model rats could be made from mother rat fed manganese deficient diet.
(5) In the patients with parenteral nutrition, trace elements (Zn, Fe. Cu, Mn. I) deficiency were induced. Basal study for the trace element drug of parenteral nutrition was developed.
(6) The method to assess nutritional(Mn)status with lymphocyte was laid.
(7) From the nutrients intake and blood trace elements concentration in Japanese and Thai, relationships between trace elements status and disease or aging were established.