Evidence map›Paper›PMID 33740966›Full record

ArticleNutrition journal2021

Meta-analysis of vitamin D supplementation and hemoglobin concentration: methodological faults obscure the interpretation of the data.

Alireza Zimorovat, Mohsen Mohammadi-Sartang, Reza Barati-Boldaji, Hamidreza Raeisi-Dehkordi

Open access · goldAbstract readLetterComment
PubMed Full text at PMC Publisher
In one paragraph

Article in Nutrition journal, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.2field-weighted citation impact, top 55% 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

1 citing paper in PubMed, 1 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

4 authors at 2 institutions in 1 country.

Alireza ZimorovatNutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Mohsen Mohammadi-SartangNutrition Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Reza Barati-BoldajiNutrition Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Hamidreza Raeisi-DehkordiNutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. hamidreza92nut@gmail.com.
Shahid Sadoughi University of Medical Sciences and Health Services · IRShiraz University of Medical Sciences · IR

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

We read the review by Arabi et al. with great interest which tried to examine the effects of vitamin D supplementation on hemoglobin concentration. It seems that the article suffers from fundamental methodological issues and the conclusions are likely to be erroneous. In this regard, we would like to ask the authors to address the mentioned limitations and to update the analysis in order to provide robust and trustful results. We are concerned that such meta-analyses may lead to the biased findings and conclusions.

Indexed as

Dietary SupplementsVitamin DHemoglobinsHumansHemoglobinsVitamin DAnemiaHemoglobinIron statusLetter to the editorVitamin D

Identifiers

PMID33740966
PMCPMC7980619
OpenAlexW3136502541

What OpenQuestion holds

Textmetadata
LicenceCC BY
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.