SynthesisBMJ open2020
Vitamin D supplementation to improve pregnancy and perinatal outcomes: an overview of 42 systematic reviews.
Synthesis in BMJ open, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
25 citing papers in PubMed, 2 syntheses or guidelines pooled it, 46 citations in OpenAlex.
- The Effects of Vitamin D Supplementation During Pregnancy on Maternal, Neonatal, and Infant Health: A Systematic Review and Meta-analysis.Nutrition reviews · 2025Pooled it
- A systematic review on estimating population attributable fraction for risk factors for small-for-gestational-age births in 81 low- and middle-income countries.Journal of global health · 2022Pooled it
- Effect of vitamin D adjuvant therapy on the proportion of regulatory T cells in peripheral blood and pregnancy outcome of patients with recurrent miscarriage.The journal of obstetrics and gynaecology research · 2025Trial
- Does antenatal cholecalciferol supplementation affect the mode or timing of delivery? Post hoc analyses of the MAVIDOS randomized controlled trial.Journal of public health (Oxford, England) · 2023Trial
- Relationship of maternal obesity and vitamin D concentrations with fetal growth in early pregnancy.European journal of nutrition · 2022Trial
- Relationship of Maternal 25-Hydroxyvitamin D₃ Deficiency With the Occurrence of Preterm Labor.Cureus · 2026Article
- Maternal fat-soluble vitamin trajectories and infant birth weight in individuals with overweight or obesity.Frontiers in endocrinology · 2026Article
- Vitamin D Supplementation During Pregnancy and Maternal and Neonatal Vitamin D Status at ≤32 Weeks Gestation: Romanian Prospective Observational Cohort Study.Children (Basel, Switzerland) · 2025Article
- Association Between 25-hydroxyvitamin D Levels and Adverse Pregnancy Outcomes in Systemic Lupus Erythematosus.Arthritis care & research · 2025Article
- Article
- Vitamin D concentration in the blood of women with twin pregnancies and in the umbilical cord blood of newborns in relation to environmental factors.Frontiers in nutrition · 2024Article
- Maternal prenatal, with or without postpartum, vitamin D3 supplementation does not improve maternal iron status at delivery or infant iron status at 6 months of age: secondary analysis of a randomised controlled trial.BMJ nutrition, prevention & health · 2023Article
- Preterm Birth and Its Association with Maternal Diet, and Placental and Neonatal Telomere Length.Nutrients · 2023Review
- Relationship between Serum 25-Hydroxyvitamin D Levels and Hormonal Status in Infertile Women: A Retrospective Study.Diagnostics (Basel, Switzerland) · 2023Article
- Is there a relation between stillbirth and low levels of vitamin D in the population? A bi-national follow-up study of vitamin D fortification.BMC pregnancy and childbirth · 2023Article
- Article
- Insights into Prevention of Health Complications in Small for Gestational Age (SGA) Births in Relation to Maternal Characteristics: A Narrative Review.Journal of clinical medicine · 2023Review
- Vitamin D - a scoping review for Nordic nutrition recommendations 2023.Food & nutrition research · 2023Article
- Review
- Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo review the evidence to assess effectiveness of vitamin D supplementation during pregnancy and associations of serum vitamin D levels with perinatal outcomes.
designOverview of systematic reviews (SRs). DATA SOURCES: Searches conducted in January 2019: Ovid Medline (1946-), Cochrane Library databases. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Two reviewers independently screened titles and abstracts, and full texts using predefined inclusion criteria: SRs evaluating vitamin D supplementation in pregnant women and/or examining the association between serum vitamin D levels reporting at least one predefined perinatal outcome. Only SRs with high AMSTAR scores were analysed. DATA EXTRACTION AND SYNTHESIS: Data were extracted independently by one reviewer and checked by a second. Results were assessed for quality independently by two reviewers using GRADE criteria.
resultsThirteen SRs were included, synthesising evidence from 204 unique primary studies. SRs of randomised controlled trials (RCTs) with the highest level of evidence showed no significant benefit from vitamin D in terms of preterm birth (RR 1.00 (95% CI 0.77, 1.30); high quality), pre-eclampsia (RR 0.91 (0.45, 1.86); low quality), gestational diabetes (RR 0.65 (0.39, 1.08); very low quality), stillbirth (RR 0.75 (0.50, 1.12); high quality), low birth weight (RR 0.74 (0.47, 1.16); low quality), caesarean section (RR 1.02 (0.93, 1.12); high quality). A significant difference was found for small for gestational age (RR 0.72 (0.52, 0.99); low quality). SRs of observational studies showed associations between vitamin D levels and preterm birth (RR 1.19 (1.08, 1.31); moderate quality), pre-eclampsia (RR 1.57 (1.21, 2.03) for 25-hydroxy vitamin D (25 (OH)D)<50 nmol/L subgroup; low quality), gestational diabetes (RR 1.12 (1.02, 1.22) for 25 (OH)D<50 nmol/L and RR 1.09 (1.03, 1.15)<75 nmol/L; moderate quality) and small for gestational age (RR 1.35 (1.18, 1.54)<50 nmol/L; low quality). SRs showed mixed results for associations between vitamin D and low birth weight (very low quality) and caesarean section (very low quality).
conclusionThere is some evidence from SRs of observational studies for associations between vitamin D serum levels and some outcomes; however SRs examining effectiveness from RCTs showed no effect of vitamin D supplementation in pregnancy with the exception of one predefined outcome, which had low quality evidence. Credibility of the evidence in this field is compromised by study limitations (in particular, the possibility of confounding among observational studies), inconsistency, imprecision and potential for reporting and publication biases.
Indexed as
Identifiers
What Socratic holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.