Stone Formers | Nonstone Formers | Urinary Ca^{2+} ≥ Cohort Median | Urinary Ca^{2+} < Cohort Median | |
---|---|---|---|---|

HPFS (n = 1037) | ||||

urinary Ca^{2+} (mg/d) | 194^{a} | 156 | 255^{c} | 121 |

urinary/dietary Ca^{2+} intake | 27%^{a} | 19% | 36%^{c} | 15% |

urinary/total Ca^{2+} intake | 22%^{a} | 16% | 31%^{c} | 13% |

NHS I (n = 1246) | ||||

urinary Ca^{2+} (mg/d) | 188^{b} | 170 | 252^{c} | 116 |

urinary/dietary Ca^{2+} intake | 25%^{b} | 21% | 38%^{c} | 16% |

urinary/total Ca^{2+} intake | 16%^{a} | 12% | 22%^{c} | 10% |

NHS II (n = 1085) | ||||

urinary Ca^{2+} (mg/d) | 204^{a} | 171 | 262^{c} | 141 |

urinary/dietary Ca^{2+} intake | 25%^{a} | 18% | 33%^{c} | 16% |

urinary/total Ca^{2+} intake | 18%^{a} | 13% | 22%^{c} | 11% |

Values are medians. Urinary/dietary Ca

^{2+}values are calculated only in participants not taking calcium supplements (HPFS,*n*= 538; NHS I,*n*= 386; and NHS II,*n*= 398).↵a

*P*values <0.01 comparing stone formers to non-stone formers.↵b

*P*values <0.05 comparing stone formers to non-stone formers.↵c

*P*values <0.01 comparing high to low urinary Ca^{2+}.