作者单位:Tufts Univ, HNRCA, Mass Spectrometry Unit, Boston, MA 02111 USA[1]Tufts Univ, Friedman Sch Nutr Sci & Policy, Boston, MA 02111 USA[2]Tufts Univ, Friedman Sch Nutr, Boston, MA 02111 USA[3]Tufts Univ, HNRCA, Bone Metab Lab, Boston, MA 02111 USA[4]Tufts Univ, Sch Med, Boston, MA 02111 USA[5]Tufts Univ, HNRCA, Metab Res Unit, Boston, MA 02111 USA[6]