Metabolism of Adolescent Girls

Abstract

In the preceding papers of this series we have reported the results of our studies on the energy, fat and protein metabolism and the excretion of creatine and creatinine of adolescent girls. In the present paper we are concerned with the metabolism of calcium, phosphorus, sodium and magnesium in the same twenty-three girls (twenty-two in the case of magnesium and sodium). METHOD OF EXPERIMENTThe technic of feeding, of collection of specimens and of preparing them for chemical analysis has been described. For mineral analysis all specimens were first wet-ashed according to the procedure described by Wang,2 and aliquots of the digested mixture were used for the various determinations. Duplicate digestions were made on each of the three day composite specimens of urine and on the dried and pulverized foods and feces.

Factors Influencing the Urinary Excretion of Calcium. I. In Normal Persons1

“…The figures required for 5 per cent significance are 0.288 and 0.304 respectively. These data tend to confirm the findings of Wang, et al (43) who found no significant correlation between weight and urinary output of calcium for 23 girls, 11 to 15 years old. Thus, while urinary calcium increases significantly with increase in weight of the individual, no direct correlation can be observed between the two.…”

Recommended Dietary Allowances

“…When the allowances that are given are plotted by age, a curve is obtained that permits interpolation for ages for which no values are given. The curve of values slopes gradually from those stated for 18 years to those for adults, beginning at 21 years. For most of the nutrients listed the values at 20 years are little different from those of 21.…”

Recommended dietary allowances

“…In arriving at the calcium allowances for children, special consideration was given to the studies by Daniels (16) and by Outhouse (17) of preschool children, and by Wang (18) of adolescent girls. The earlier studies by Sherman and Hawley (19) and by Wang and coworkers (20) were also evaluated, as were the calculations made by Leitch (9) as to the probable requirements during the period of growdh.…”

“…(1) Numerous wddely distributed instances have been found in which individuals who revealed no other basis for functional impairment characterized by macrocytic anemia and associated tissue changes, responded promptly to folic acid therapy, using either the synthetic or the highly [18] purified natural product (pteroylglutamic acid). The dietary histories of these patients have been characterized, in most cases, by an intake of foods that would provide only very small quantities of fohc acid.…”