Calcium Needs of Children Calcium needs vary at different stages of life because of differing rates of bone growth and calcium utilization. Match the life stage with recommended calcium intakes (RDAs) for each stage. a. 9- to 18-year-old boys and girls: (Click to select) b. 4-to 8-year-old boys and girls: (Click to select) c. 1- to 3-year-old boys and girls: (click to select)