Variability of Metabolic Response of Different Children to a Given Intake of Calcium

As the metabolic balance studies on the “so-called normal” adults1,2 and 22 children3,4 as well as the growth observations on 530 infants5 have progressed in this laboratory over several years we have grown more and more impressed with the wide physiological variations found. These fluctuations are evident not only among individuals of the same age, body size and living under the same environmental conditions but of the same individual when kept under constant conditions and observed continuously over, not days, but weeks. Obviously, it becomes necessary to build up some knowledge as to how much variation one may expect to find in a healthy individual living under highly standardized conditions before it is possible to interpret the degree of differences of results found under specific experimental conditions or in disease. Moreover, in the case of children, it is exceedingly important to build up some concept of the changes that occur incident to growth and development alone, before one is able to interp...