A Longitudinal Study of the Calcium Intake of Children from One to Eighteen Years of Age

The cross-sectional distributions of the calcium intakes of sixty-four boys and sixty-one girls of the Maturity Series of this longitudinal research are presented for the age period one to eighteen years. Wide variations with age and sex are clearly shown. While the average calcium intakes for the two sexes are similar in the preschool years, during the school years, and especially the late school years, the boys calcium intakes were higher than the girls. The boys calcium intakes were always highest at eighteen years when the average value was 1.65 gm. per day; the maximum for the girls was reached between fifteen and sixteen years and was 1.28 gm. per day; it was 1.22 gm. per day at eleven to twelve years whereas the average for the boys was 1.28 gm. per day for the same interval. While the boys average calcium intake continued to rise to eighteen years (the last observed period), the girls mean fell to 1.08 gm. per day at eighteen years. In order to view our data longitudinally in terms of individual patterns of consumption of calcium, the boys and girls in the Maturity Series were classified according to their levels of calcium intake into pattern groups by a procedure described in the text, using cumulative values of calcium intakes within specified age periods. The frequency of occurrence of the longitudinal patterns of calcium intake are shown as well as the gradation of difference in levels of calcium intake for the boys and girls of the Maturity Series and the direction and rate of change with patterns and within pattern groups.