Evidence map›Paper›PMID 34806158›Full record

SynthesisCNS drugs2021

Vitamin D Supplementation and Cognition in Adults: A Systematic Review of Randomized Controlled Trials.

Olivier Beauchet, Liam A Cooper-Brown, Gilles Allali

Abstract readSystematic Review
PubMed Publisher
In one paragraph

Synthesis in CNS drugs, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 21 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
21citing papers in PubMed, 2 pooled it
2.9field-weighted citation impact, top 9% 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

21 citing papers in PubMed, 2 syntheses or guidelines pooled it, 32 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
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  16. Review
  17. Role of Calcitriol and Vitamin D Receptor (International journal of molecular sciences · 2024
    Review
  18. Review
  19. Article
  20. Vitamin D supplementation and incident dementia: Effects of sex,Alzheimer's & dementia (Amsterdam, Netherlands)
    Article
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

3 authors at 3 institutions in 3 countries.

Olivier BeauchetDepartment of Medicine, University of Montreal, Montreal, QC, Canada. olivier.beauchet@umontreal.ca.ORCID http://orcid.org/0000-0003-2534-4830
Liam A Cooper-BrownFaculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada.
Gilles AllaliLeenaards Memory Center, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
McGill University Health Centre · CANanyang Technological University · SGUniversity of Lausanne · CH

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe role of vitamin D supplementation in improving cognition and slowing the incidence of minor and major neurocognitive disorders is a matter of debate. To our knowledge, no systematic review of randomized controlled trials (RCTs) has examined this question in adults.

objectivesThe purpose of this systematic review is to synthesize the evidence regarding the effects of vitamin D supplementation on cognitive performance and neurocognitive disorders in adults.

methodsA systematic search of scientific articles in English or French was conducted. The MEDLINE (PubMed), EMBASE (Ovid, EMBASE), PsychINFO, and Cochrane Central databases were searched for records without any limit on publication date in May 2021. Inclusion criteria were (1) human participants, (2) RCT, (3) participant age ≥ 18, (4) vitamin D supplementation as the intervention, and (5) cognition (i.e., cognitive performance or cognitive status such as cognitively healthy or minor and major neurocognitive disorder) as the primary outcome. Two independent reviewers both assessed all eligible studies' full texts and the risk of bias arising from methodological issues using a standardized procedure.

resultsOf the 2137 abstracts identified, 61 (2.9%) met screening inclusion criteria. After full text examination, 41 records (67.2%) were excluded. As a result, 20 RCTs (32.8%) were included in the systematic review. The review yielded mixed findings and, thus, failed to find evidence supporting cognitive benefits from vitamin D supplementation or suggesting a causal association between vitamin D and cognitive function. Half of the RCTs reported mixed results, one quarter negative results, and the last quarter positive effects for vitamin D supplementation on cognitive performance. The variability in serum 25-dihydroxyvitamin D concentration thresholds, the cognitive tests employed, the supplementation doses, and the samples' characteristics (i.e., ethnicity or number of participants) may explain these mixed findings.

conclusionThis systematic review of RCTs does not support a role for vitamin D supplementation in enhancing cognition in adults.

Indexed as

Dietary SupplementsCognitionCognition DisordersHumansRandomized Controlled Trials as TopicVitamin DVitamin D

Identifiers

PMID34806158
OpenAlexW3217624600

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.