Evidence map›Paper›PMID 26244032›Full record

ArticleOpen access journal of sports medicine2015

Effects of vitamin D and quercetin, alone and in combination, on cardiorespiratory fitness and muscle function in physically active male adults.

Shane D Scholten, Igor N Sergeev, Qingming Song, Chad B Birger

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

Article in Open access journal of sports medicine, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 21 papers, 5 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
21citing papers in PubMed, 5 pooled it
2.0field-weighted citation impact, top 15% 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, 5 syntheses or guidelines pooled it, 31 citations in OpenAlex.

  1. Pooled it
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  6. Trial
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  9. Vitamin DEuropean journal of nutrition · 2017
    Trial
  10. Article
  11. Significance of 8-iso-PGFAmerican heart journal plus : cardiology research and practice · 2026
    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

4 authors at 2 institutions in 1 country.

Shane D ScholtenExercise and Sport Sciences, Augustana College, Sioux Falls, USA.
Igor N SergeevDepartment of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, USA.
Qingming SongGold Green Farm Corporation, Hammonton, NJ, USA.
Chad B BirgerCenter for Health Outcomes and Prevention Research, Sanford Research, Sioux Falls, SD, USA.
Sanford Research · USSouth Dakota State University · US

Funding

Wichozani-A Healthy Lifestyle for Rural American Indian Youth through Cultural and Physical Activities: A Community-Based Participatory Research StudyP20GM103443 · NIGMS · UNIVERSITY OF SOUTH DAKOTA · PI Ryan Michael Johnson · 2012 to 2026
$58.1M
NIGMS NIH HHS P20 GM103443
6 · The paper itself

Abstract

introductionVitamin D and the antioxidant quercetin, are promising agents for improving physical performance because of their possible beneficial effects on muscular strength and cardiorespiratory fitness. PURPOSE: The purpose of this study was to determine the effects of increased intakes of vitamin D, quercetin, and their combination on antioxidant status, the steroid hormone regulators of muscle function, and measures of physical performance in apparently healthy male adults engaged in moderate-to-vigorous-intensity exercise training.

methodsA total of 40 adult male participants were randomized to either 4,000 IU vitamin D/d, 1,000 mg/d quercetin, vitamin D plus quercetin, or placebo for 8 weeks. Measures of cardiorespiratory fitness and muscle function, blood markers for antioxidant and vitamin D status, and hormones 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and testosterone were measured pre- and postsupplementation.

resultsAt enrollment, 88.6% of participants were vitamin D sufficient (serum 25-hydroxyvitamin D >50 nmol/L) and had normal serum testosterone levels. Supplementation with vitamin D significantly increased serum 25(OH)D concentration (by 87.3% in the vitamin D group, P<0.001) and was associated with an increasing trend of testosterone concentration. There were no changes in concentration of 1,25(OH)2D3 and markers of antioxidant status associated with vitamin D or quercetin supplementation. No improvements in physical performance measures associated with vitamin D and quercetin supplementation were found.

conclusionThe findings obtained demonstrate that long-term vitamin D and quercetin supplementation, alone or in combination, does not improve physical performance in male adults with adequate vitamin D, testosterone, and antioxidant status.

Indexed as

25-hydroxyvitamin Dantioxidant statusoxidative stressphysical performancetestosterone

Identifiers

PMID26244032
PMCPMC4521671
OpenAlexW1716070878

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
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.