TY - JOUR
T1 - Effect of calcium supplementation on bone resorption in pregnancy and the early postpartum
T2 - A randomized controlled trial in Mexican Women
AU - Ettinger, Adrienne S.
AU - Lamadrid-Figueroa, Héctor
AU - Mercado-García, Adriana
AU - Kordas, Katarzyna
AU - Wood, Richard J.
AU - Peterson, Karen E.
AU - Hu, Howard
AU - Hernández-Avila, Mauricio
AU - Téllez-Rojo, Martha M.
N1 - Funding Information:
The authors gratefully acknowledge the contribution of the American British Cowdray Hospital in Mexico City for use of its research facilities. This work was supported by the U.S. National Institutes of Health (NIH) [grant numbers: P42-ES05947, R01-ES07821, R01-ES021446, P30-ES00002, and K01-ES014907] and by México Consejo Nacional de Ciencia y Tecnología (CONACYT) (The National Council of Science and Technology) [grant number 4150M9405]. The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.
Publisher Copyright:
© 2014 Ettinger et al.
PY - 2014
Y1 - 2014
N2 - Background: Calcium needs are physiologically upregulated during pregnancy and lactation to meet demands of the developing fetus and breastfeeding infant. Maternal calcium homeostasis is maintained by hormonal adaptive mechanisms, thus, the role of dietary calcium supplementation in altering maternal responses to fetal-infant demand for calcium is thought to be limited. However, increased calcium absorption is directly related to maternal calcium intake and dietary supplementation has been suggested to prevent transient bone loss associated with childbearing. Methods: In a double-blind, randomized placebo-controlled trial, we randomly assigned 670 women in their first trimester of pregnancy to 1,200 mg/day calcium (N = 334) or placebo (N = 336). Subjects were followed through 1-month postpartum and the effect on urinary cross-linked N-telopeptides (NTx) of type I collagen, a specific marker of bone resorption, was evaluated using an intent-to-treat analysis. Women with a baseline and at least one follow-up measurement (N = 563; 84%) were included. Subsequent analyses were conducted stratifying subjects by compliance assessed using pill counts. In random subsets of participants, bone-specific alkaline phosphatase (BAP) (N = 100) and quantitative ultrasound (QUS) (N = 290) were also measured. Results: Calcium was associated with an overall reduction of 15.8% in urinary NTx relative to placebo (p < 0.001). Among those who consumed ≥50%, ≥67%, and ≥75% of pills, respectively, the effect was associated with 17.3%, 21.3%, and 22.1% reductions in bone resorption (all p < 0.001). There was no significant effect of calcium on bone formation measured by BAP. However, by 1-month postpartum, those in the calcium group had significantly lower NTx/BAP ratios than those in the placebo group (p ≥ 0.04) indicating a net reduction in bone loss in the supplement group by the end of follow-up. Among subjects who consumed ≥50% and ≥75% of pills, respectively, calcium was also associated with an increase of 26.3 m/s (p ≥ 0.03) and 59.0 m/s (p ≥ 0.009) in radial SOS relative to placebo by 1-month postpartum. Conclusions: Calcium administered during pregnancy and the early postpartum period, to women with intakes around adequacy, was associated with reduced bone resorption and, thus, may constitute a practical intervention to prevent transient skeletal loss associated with childbearing.
AB - Background: Calcium needs are physiologically upregulated during pregnancy and lactation to meet demands of the developing fetus and breastfeeding infant. Maternal calcium homeostasis is maintained by hormonal adaptive mechanisms, thus, the role of dietary calcium supplementation in altering maternal responses to fetal-infant demand for calcium is thought to be limited. However, increased calcium absorption is directly related to maternal calcium intake and dietary supplementation has been suggested to prevent transient bone loss associated with childbearing. Methods: In a double-blind, randomized placebo-controlled trial, we randomly assigned 670 women in their first trimester of pregnancy to 1,200 mg/day calcium (N = 334) or placebo (N = 336). Subjects were followed through 1-month postpartum and the effect on urinary cross-linked N-telopeptides (NTx) of type I collagen, a specific marker of bone resorption, was evaluated using an intent-to-treat analysis. Women with a baseline and at least one follow-up measurement (N = 563; 84%) were included. Subsequent analyses were conducted stratifying subjects by compliance assessed using pill counts. In random subsets of participants, bone-specific alkaline phosphatase (BAP) (N = 100) and quantitative ultrasound (QUS) (N = 290) were also measured. Results: Calcium was associated with an overall reduction of 15.8% in urinary NTx relative to placebo (p < 0.001). Among those who consumed ≥50%, ≥67%, and ≥75% of pills, respectively, the effect was associated with 17.3%, 21.3%, and 22.1% reductions in bone resorption (all p < 0.001). There was no significant effect of calcium on bone formation measured by BAP. However, by 1-month postpartum, those in the calcium group had significantly lower NTx/BAP ratios than those in the placebo group (p ≥ 0.04) indicating a net reduction in bone loss in the supplement group by the end of follow-up. Among subjects who consumed ≥50% and ≥75% of pills, respectively, calcium was also associated with an increase of 26.3 m/s (p ≥ 0.03) and 59.0 m/s (p ≥ 0.009) in radial SOS relative to placebo by 1-month postpartum. Conclusions: Calcium administered during pregnancy and the early postpartum period, to women with intakes around adequacy, was associated with reduced bone resorption and, thus, may constitute a practical intervention to prevent transient skeletal loss associated with childbearing.
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U2 - 10.1186/1475-2891-13-116
DO - 10.1186/1475-2891-13-116
M3 - Article
C2 - 25511814
AN - SCOPUS:84965094875
SN - 1475-2891
VL - 13
JO - Nutrition Journal
JF - Nutrition Journal
IS - 1
M1 - 116
ER -