title: The effects of different levels of calcium supplementation on the bone mineral status of postpartum lactating Chinese women: a 12-month randomised, double-blinded, controlled trial.
abstract: Increasing dietary Ca intake may prevent the excessive mobilisation of bone mineral in nursing mothers. We aimed to investigate whether higher Ca intake could positively modulate the bone mineral changes in Chinese postpartum lactating women. The study was a 12-month randomised, double-blinded, parallel group trial conducted over 12 months. A total of 150 postpartum women were randomly selected to receive either 40 g of milk powder containing 300 mg of Ca and 5 μg of vitamin D (Low-Ca group) or same milk powder additionally fortified with 300 mg of Ca (Mid-Ca group) or 600 mg of Ca (High-Ca group). Bone mineral density (BMD) for the whole body, the lumbar spine, the total left hip and its sub-regions was measured using dual-energy X-ray absorptiometry. A total of 102 subjects completed the whole trial. The duration of total lactating time was 7·9 (SD 2·8) months on average. The intention-to-treat analysis yielded the following mean percentage changes in BMD for the whole body, the lumbar spine and the total left hip, respectively: -0·93 (SD 1·97), 2·11 (SD 4·90) and -1·60 (SD 2·65)% for the Low-Ca group; -0·56 (SD 1·89), 2·21 (SD 3·77) and -1·43 (SD 2·30)% for the Mid-Ca group; and -0·44 (SD 1·67), 2·32 (SD 4·66) and -0·95 (SD 4·08)% for the High-Ca group. The differences between the groups were not statistically significant (P: 0·5-0·9). The results of the complete case analysis were similar. In sum, we found no significant differences in the bone mineral changes from baseline to 12 months in postpartum lactating women consuming milk powder fortified with different levels of Ca.
authors.affiliation: 1Guangdong Provincial Key Laboratory of Tropical Disease Research,School of Public Health and Tropical Medicine,Southern Medical University,Guangzhou,510515,People's Republic of China.
authors.forename: Zhe-Qing
authors.initials: ZQ
authors.lastname: Zhang
authors.affiliation: 2Guangdong Provincial Key Laboratory of Food, Nutrition, and Health,School of Public Health,Sun Yat-sen University,Guangzhou,Guangdong,510080,People's Republic of China.
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Chen
authors.affiliation: 2Guangdong Provincial Key Laboratory of Food, Nutrition, and Health,School of Public Health,Sun Yat-sen University,Guangzhou,Guangdong,510080,People's Republic of China.
authors.forename: Ruo-Qin
authors.initials: RQ
authors.lastname: Wang
authors.affiliation: 3Chinese Center for Disease Control and Prevention,Institute of Nutrition and Food Safety,Beijing 100000,People's Republic of China.
authors.forename: Zhen-Wu
authors.initials: ZW
authors.lastname: Huang
authors.affiliation: 3Chinese Center for Disease Control and Prevention,Institute of Nutrition and Food Safety,Beijing 100000,People's Republic of China.
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Yang
authors.affiliation: 2Guangdong Provincial Key Laboratory of Food, Nutrition, and Health,School of Public Health,Sun Yat-sen University,Guangzhou,Guangdong,510080,People's Republic of China.
authors.forename: Yi-Xiang
authors.initials: YX
authors.lastname: Su
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000818:Animals; D015519:Bone Density; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D001942:Breast Feeding; D002113:Calcification, Physiologic; D002118:Calcium / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005527:Food, Fortified; D006615:Hip; D006801:Humans; D007774:Lactation / Q000378:metabolism*; D008159:Lumbar Vertebrae; D008892:Milk; D008903:Minerals / Q000378:metabolism / Q000494:pharmacology; D049590:Postpartum Period; D014807:Vitamin D / Q000494:pharmacology; D055815:Young Adult
chemical_list: D002136:Calcium, Dietary; D008903:Minerals; D014807:Vitamin D; D002118:Calcium
keywords: BMC bone mineral content; BMD bone mineral density; Bone mineral density; Calcium; Chinese; Milk; Postpartum women