{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T18:37:54Z","timestamp":1793299074314,"version":"4.5.0"},"reference-count":64,"publisher":"Wiley","issue":"11","license":[{"start":{"date-parts":[[2022,6,28]],"date-time":"2022-06-28T00:00:00Z","timestamp":1656374400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["BJOG"],"published-print":{"date-parts":[[2022,10]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Calcium supplementation reduces the risk of pre\u2010eclampsia, but questions remain about the dosage to prescribe and who would benefit most.<\/jats:p><\/jats:sec><jats:sec><jats:title>Objectives<\/jats:title><jats:p>To evaluate the effectiveness of high (\u22651\u00a0g\/day) and low (&lt;1\u00a0g\/day) calcium dosing for pre\u2010eclampsia prevention, according to baseline dietary calcium, pre\u2010eclampsia risk and co\u2010interventions, and intervention timing.<\/jats:p><\/jats:sec><jats:sec><jats:title>Search strategy<\/jats:title><jats:p>CENTRAL, PubMed, Global Index Medicus and CINAHL, from inception to 2 February 2021, clinical trial registries, reference lists and expert input (CRD42018111239).<\/jats:p><\/jats:sec><jats:sec><jats:title>Selection criteria<\/jats:title><jats:p>Randomised controlled trials of calcium supplementation for pre\u2010eclampsia prevention, for women before or during pregnancy. Network meta\u2010analysis (NMA) also included trials of different calcium doses.<\/jats:p><\/jats:sec><jats:sec><jats:title>Data collection and analysis<\/jats:title><jats:p>Two independent reviewers extracted published data. The meta\u2010analysis employed random\u2010effects models and the NMA, a Bayesian random\u2010effects model, to obtain direct and indirect effect estimates.<\/jats:p><\/jats:sec><jats:sec><jats:title>Main results<\/jats:title><jats:p>The meta\u2010analysis included 30 trials (<jats:italic>N<\/jats:italic>\u00a0=\u00a020\u2009445 women), and the NMA to evaluate calcium dosage included 25 trials (<jats:italic>N<\/jats:italic>\u00a0=\u00a015\u2009038). Calcium supplementation prevented pre\u2010eclampsia similarly with a high dose (RR\u00a00.49, 95%\u00a0CI 0.36\u20130.66) or a low dose (RR\u00a00.49, 95%\u00a0CI 0.36\u20130.65). By NMA, high\u2010dose (vs low\u2010dose) calcium did not differ in effect (RR\u00a00.79, 95%\u00a0CI 0.43\u20131.40). Calcium was similarly effective regardless of baseline pre\u2010eclampsia risk, vitamin\u2009D co\u2010administration or timing of calcium initiation, but calcium was ineffective among women with adequate average baseline calcium intake.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Low\u2010 and high\u2010dose calcium supplementation are effective for pre\u2010eclampsia prevention in women with low calcium intake. This has implications for population\u2010level implementation where dietary calcium is low, and targeted implementation where average intake is adequate.<\/jats:p><\/jats:sec><jats:sec><jats:title>Tweetable abstract<\/jats:title><jats:p>A network meta\u2010analysis of 25 trials found that low\u2010dose calcium supplementation (&lt;1\u00a0g\/day) is as effective as high\u2010dose calcium supplementation (\u22651\u00a0g\/day) in halving the risk of pre\u2010eclampsia when baseline calcium intake is low.<\/jats:p><\/jats:sec>","DOI":"10.1111\/1471-0528.17222","type":"journal-article","created":{"date-parts":[[2022,5,21]],"date-time":"2022-05-21T04:29:31Z","timestamp":1653107371000},"page":"1833-1843","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":80,"title":["Calcium for pre\u2010eclampsia prevention: A systematic review and network meta\u2010analysis to guide personalised antenatal care"],"prefix":"10.1111","volume":"129","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5846-3014","authenticated-orcid":false,"given":"Mai\u2010Lei","family":"Woo Kinshella","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynaecology and British Columbia Children's Hospital Research Institute University of British Columbia  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Catherine","family":"Sarr","sequence":"additional","affiliation":[{"name":"Department of Women and Children's Health, School of Life Course Sciences King's College London  London UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akshdeep","family":"Sandhu","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology and British Columbia Children's Hospital Research Institute University of British Columbia  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7704-1677","authenticated-orcid":false,"given":"Jeffrey N.","family":"Bone","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology and British Columbia Children's Hospital Research Institute University of British Columbia  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marianne","family":"Vidler","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology and British Columbia Children's Hospital Research Institute University of British Columbia  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sophie E.","family":"Moore","sequence":"additional","affiliation":[{"name":"Department of Women and Children's Health, School of Life Course Sciences King's College London  London UK"},{"name":"The Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine  Serekunda Gambia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rajavel","family":"Elango","sequence":"additional","affiliation":[{"name":"School of Population and Public Health and Department of Pediatrics BC Children's and Women's Hospital and University of British Columbia  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriela","family":"Cormick","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Epidemiol\u00f3icas y Salud P\u00falica (CIESP\u2010IECS), Consejo Nacional de Investigaciones Cient\u00edficas y T\u00e9cnicas (CONICET)  Ciudad de Buenos Aires Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8412-3010","authenticated-orcid":false,"given":"Jos\u00e9 M.","family":"Belizan","sequence":"additional","affiliation":[{"name":"Centro de Investigaciones Epidemiol\u00f3icas y Salud P\u00falica (CIESP\u2010IECS), Consejo Nacional de Investigaciones Cient\u00edficas y T\u00e9cnicas (CONICET)  Ciudad de Buenos Aires Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3080-1007","authenticated-orcid":false,"given":"G. 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