Evidence map›Paper›PMID 26219612›Full record

ReviewJournal of endocrinological investigation2015

Vitamin D during pregnancy: why observational studies suggest deficiency and interventional studies show no improvement in clinical outcomes? A narrative review.

S N Karras, P Anagnostis, D Naughton, C Annweiler, A Petroczi, D G Goulis

Open access · greenAbstract readReview
PubMed Publisher
In one paragraph

Review in Journal of endocrinological investigation, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
23citing papers in PubMed, 4 pooled it
4.2field-weighted citation impact, top 6% of its field
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

23 citing papers in PubMed, 4 syntheses or guidelines pooled it, 36 citations in OpenAlex.

  1. Pooled it
  2. Efficacy of Vitamin DNutrients · 2020
    Pooled it
  3. Pooled it
  4. Pooled it
  5. Trial
  6. Article
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  10. Article
  11. Review
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  14. Vitamin D and Gestational Diabetes Mellitus: Is There a Link?Antioxidants (Basel, Switzerland) · 2019
    Review
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  16. Review
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 3 institutions in 4 countries.

S N KarrasUnit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece. karraspiros@yahoo.gr.
P AnagnostisUnit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
D NaughtonSchool of Life Sciences, Kingston University, Kingston upon Thames, London, UK.
C AnnweilerRobarts Research Institute, The University of Western Ontario, London, ON, Canada.
A PetrocziSchool of Life Sciences, Kingston University, Kingston upon Thames, London, UK.
D G GoulisUnit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Aristotle University of Thessaloniki · GRKingston University · GBWestern University · CA

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

A considerable number of studies have examined vitamin D status during pregnancy. Although data from observational studies denote vitamin D hypovitaminosis (deficiency or insufficiency) during pregnancy is associated with a plethora of adverse maternal and neonatal outcomes, data from interventional (supplementation) trials fail to reveal a significant impact on maternal and offspring health. The aim of this narrative review was to critically appraise the methodology of the most representative published randomized controlled trials in an attempt to explain the difference between observational and supplementation results. We found that this difference could be attributed to a variety of factors, namely: (i) study design (lack of a specific outcome in conjunction with timing of supplementation, enrolment of participants with heterogeneous vitamin D status); (ii) pitfalls in the interpretation of vitamin D equilibrium (lack of determination of plasma half-life); (iii) supplementation regimen (administration of a wide range of regimens, in terms of dose, bolus and form); (iv) geographical characteristics (vitamin D needs could vary significantly within a country, particularly in areas with a wide range of latitude gradient); (v) adaptations of vitamin D metabolism during pregnancy (vitamin D and calcium equilibrium are changed during pregnancy compared with the non-pregnant state) and (vi) supplementation of populations with low baseline 25(OH)D values would likely manifest beneficial effects. All these parameters should be taken into consideration in the design of future vitamin D supplementation trials.

Indexed as

Observational Studies as TopicOutcome Assessment, Health CareRandomized Controlled Trials as TopicFemaleHumansPregnancyPregnancy ComplicationsVitamin DVitamin D DeficiencyVitamin DHypovitaminosis DPregnancyRandomized controlled trialVitamin D

Identifiers

PMID26219612
OpenAlexW963041299

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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 OpenQuestion graph.