Current calcium recommendations in North America.

Calcium recommendations in North America set in 1997 were determined as the intake for maximal retention in age groups for which these data were available. Because there is a linear relationship between bone density and fracture risk and because 99% of calcium resides in the bone, it was thought that maximizing calcium retention is an optimal goal for bone health. Typically, data for only one gender and race were available in an age group. Recent evidence suggests that calcium intakes for maximal retention may not vary by subgroup even if calcium retention is vastly different at any given intake. Issues that are receiving attention currently include possible catch up growth, dairy vs. calcium intake, and how to establish optimal intakes.