Dietary reference intake for Japanese was revised for use from 2000 to 2004. It was included not only the recommended dietary allowances but also new tolerable upper intake levels (UL) . The UL of calcium is 2,500 mg/day and the level has been decided by a model of the risk assessment by lowest observed adverse effect level with uncertain factors such as the sensitivity for individuals. The way how to decide Japanese UL levels has mostly referred to those by American National Academy of Science. Enough calcium intake is necessary for accumulating optimal peak bone mass in the young and also for suppressing the decrease in bone density in the old, however, too much high intake of calcium will have adverse effect on balance of other minerals.