Abstract
This review includes the following topics:(1) A historical sketch of researches on trace elements, which are now at dawn of the new age, was given briefly. (2) Comments and interpretations were given on trends and changes in nutritional requirements of iron, zinc and copper by recommended dietary allowance and dietary reference intakes for Japanese. (3)Discussion was made on intake amounts of iron, zinc and copper by national health and nutrition survey in Japan. In 2003, it is calculated that the population ratio of intake amounts less than estimated average requirements was highest (80%) in iron intake of female followed by iron intake of male and zinc intake of male and female(about 30%) and was lowest (less than 5%) in copper intake of male and female in the age group 30∼49.
Generally, there is a tendency that requirements, estimated intake amounts, normal levels in blood or serum and the content of foods in regard to trace elements have been decreased year by year as a consequence of the development and improvement of analytical methods.
