Including Bergel E, Cormick G, Hall DR, Fawcus S, Lazaga Betran AP, Munjanja S, Novikova N, Oyebajo A, Purnat T, Roberts JM, Sawchuck D and Singata M.
Low-dose calcium supplementation for preventing pre-eclampsia: a systematic review and commentary
Article first published online: 13 MAR 2014
©2014 The Authors. BJOG An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 121, Issue 8, pages 951–957, July 2014
How to Cite
on behalf of the calcium and pre-eclampsia (CAP) study Group. Low-dose calcium supplementation for preventing pre-eclampsia: a systematic review and commentary. BJOG 2014;121:951–957., , .
- Issue published online: 24 JUN 2014
- Article first published online: 13 MAR 2014
- Manuscript Accepted: 13 OCT 2013
- Effective Care Research Unit from the University of British Columbia
- Calcium replacement;
- calcium supplement;
- low-dose calcium;
Epidemiological data link low dietary calcium with pre-eclampsia. Current recommendations are for 1.5–2 g/day calcium supplementation for low-intake pregnant women, based on randomised controlled trials of ≥1 g/day calcium supplementation from 20 weeks of gestation. This is problematic logistically in low-resource settings; excessive calcium may be harmful; and 20 weeks may be too late to alter outcomes.
To review the impact of lower dose calcium supplementation on pre-eclampsia risk.
Search strategy and selection criteria
We searched PubMed and the Cochrane Pregnancy and Childbirth Group trials register.
Data collection and analysis
Two authors extracted data from eligible randomised and quasi-randomised trials of low-dose calcium (LDC, <1 g/day), with or without other supplements.
Pre-eclampsia was reduced consistently with LDC with or without co-supplements (nine trials, 2234 women, relative risk [RR] 0.38; 95% confidence interval [95% CI] 0.28–0.52), as well as for subgroups: LDC alone (four trials, 980 women, RR 0.36; 95% CI 0.23–0.57]); LDC plus linoleic acid (two trials, 134 women, RR 0.23; 95% CI 0.09–0.60); LDC plus vitamin D (two trials, 1060 women, RR 0.49; 0.31–0.78) and a trend for LDC plus antioxidants (one trial, 60 women, RR 0.24; 95% CI 0.06–1.01). Overall results were consistent with the single quality trial of LDC alone (171 women, RR 0.30; 95% CI 0.06–1.38). LDC plus antioxidants commencing at 8–12 weeks tended to reduce miscarriage (one trial, 60 women, RR 0.06; 95% CI 0.00–1.04).
These limited data are consistent with LDC reducing the risk of pre-eclampsia; confirming this in sufficiently powered randomised controlled trials would have implications for current guidelines and their global implementation.