WEST LAFAYETTE, Ind. -- The amount of calcium adolescents need to achieve maximum bone growth has been determined for the first time by a research team at Purdue University. The research shows that adolescents need 1,300 milligrams per day -- an amount found in four and a half cups of milk or yogurt.
Connie Weaver, head of Purdue's Department of Food and Nutrition, says "before the amount of calcium needed by adolescents was just an estimate."
The new data were instrumental in developing the revised Recommended Dietary Allowances, which were announced Wednesday (8/13). The recommendations are produced by the National Academy of Sciences and used by the Food and Drug Administration and others.
The new Recommended Dietary Allowance (which the National Academy of Sciences is renaming the Dietary Reference Intake, or DRI) calls for between 1,000 and 1,300 milligrams of calcium per day. For adolescents in age groups 9 to 13 and 14 to 18, the new recommendations call for 1,300 milligrams of calcium per day.
Distinguishing between adolescents and adults in the guidelines is important, Weaver says, because bone growth occurs almost exclusively during adolescence, or during the years following the onset of puberty for women. "Your window of opportunity for bone growth occurs while you're pretty young," she says.
Weaver and other researchers from Purdue and the Indiana University School of Medicine determined that an intake of 1,300 milligrams of calcium per day offered maximum bone growth for females ages 12 to 15. "That's important, because the more bone you build up early in life, the more you can use up later in life," Weaver says.
Purdue nutritional educator Lisa Jackman, the primary investigator on this research study, says, "The new numbers for adolescents are based on our research, which is also just being released. This information is completely up-to-date."