| Autor: |
O'Brien, Kimberly O., Donangelo, Carmen M., Vargas Zapata, Carmiña L., Abrams, Steven A., Martin Spencer, E., King, Janet C. |
| Zdroj: |
American Journal of Clinical Nutrition; Feb2006, Vol. 83 Issue 2, p317-323, 7p |
| Abstrakt: |
Background: Few data exist on longitudinal changes in bone calcium turnover rates across pregnancy and lactation. Objective: Our aim was to characterize calcium kinetic variables and predictors of these changes across pregnancy and early lactation in women with low calcium intakes. Design: Stable calcium isotopes were administered to 10 Brazilian women during early pregnancy (EP; weeks 10-12 of gestation), late pregnancy (LP; weeks 34-36 of gestation), and early lactation (EL; 7-8 wk postpartum). Multicompartmental modeling was used to assess the rates of bone calcium turnover in relation to calcium intakes and circulating concentrations of parathyroid hormone (PTH), insulin-like growth factor 1, and 1,25-dihydroxyvitamin D. Results: Rates of bone calcium deposition increased significantly from EP to LP (P ⩽ 0.001) and were significantly associated with serum PTH during LP (P⩽0.01). Rates of bone calcium resorption were also higher during LP and EL than during EP (P ⩽ 0.01) and were associated with both PTH (P ⩽ 0.01) and IGF-1 (P ⩽ 0.05) during LP but not during EL. Net balance in bone calcium turnover was positively associated with dietary calcium duringEP(P⩽0.01), LP (P⩽0.01), and EL (P⩽0.01). The mean (±SD) calcium intake was 463 ± 182 mg/d and, in combination with insulin-like growth factor 1, explained 68-94% of the variability in net bone calcium balance during pregnancy and lactation. Conclusions: Net deficits in bone calcium balance occurred during pregnancy and lactation. Increased dietary calcium intake was associated with improved calcium balance; therefore, greater calcium intakes may minimize bone loss across pregnancy and lactation in women with habitual intakes of <500 mg calcium/d. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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