To a great extent, individuals are protected from excess intakes of calcium by a tightly
regulated intestinal absorption and elimination mechanism through the action of 1,25-
dihydroxyvitamin D, the hormonally active form of vitamin D. When calcium is
absorbed in excess of need, the excess is excreted by the kidney in healthy people
who do not have renal impairment. Concern for excess calcium intake is directed
primarily to those who are prone to milk alkali syndrome (the simultaneous presence