title: Effects of vitamin D supplementation during pregnancy on neonatal vitamin D and calcium concentrations: a systematic review and meta-analysis.
abstract: We conducted a meta-analysis to review the effects of vitamin D supplementation during pregnancy on neonatal 25-hydroxyvitamin D (25(OH)D) and calcium concentrations. Randomized controlled trials that supplemented subjects with vitamin D2 or D3 during pregnancy and reported cord blood 25(OH)D or calcium concentrations were included. A random-effect model was used to pool the data. Subgroup analyses were performed to explore the sources of heterogeneity. We searched PubMed, Web of Science, and Cochrane Library for relevant publications. Among 1768 publications identified by our search strategy, 13 studies met our inclusion criteria. Cord blood 25(OH)D concentration was significantly increased by maternal vitamin D supplementation (mean difference, 22.48 nmol/L; 95% confidence interval, 15.90-29.06 nmol/L) with high heterogeneity (I2 = 98.8%, P < .0001). No effects on cord blood calcium concentration was reported (mean difference, 0.05 mmol/L; 95% confidence interval, -0.04-0.13 mmol/L). Supplementation regimens and the different control groups may be the major sources of heterogeneity. Vitamin D supplementation during pregnancy can improve cord blood 25(OH)D concentration in women with low 25(OH)D concentration, but does not affect cord blood calcium concentration. Future researches are needed to evaluate the effect of maternal vitamin D supplementation in women with a normal 25(OH)D concentration and explore the combined effects of vitamin D, calcium, and multivitamins.
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, School of Public Health, Peking University, Beijing, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, School of Public Health, Peking University, Beijing, PR China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, PR China.
authors.forename: Zhixia
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, School of Public Health, Peking University, Beijing, PR China.
authors.forename: Sen
authors.initials: S
authors.lastname: Chen
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, School of Public Health, Peking University, Beijing, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, School of Public Health, Peking University, Beijing, PR China. Electronic address: yerw@bjmu.edu.cn.
authors.forename: Rongwei
authors.initials: R
authors.lastname: Ye
mesh_terms: D002118:Calcium / Q000097:blood*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*; D014815:Vitamins / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium
keywords: Calcium; Meta-analysis; Neonate; Pregnancy; Vitamin D