Evidence map›Paper›PMID 32958033›Full record

SynthesisJournal of the International Society of Sports Nutrition2020

The bright and the dark sides of L-carnitine supplementation: a systematic review.

Angelika K Sawicka, Gianluca Renzi, Robert A Olek

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

Synthesis in Journal of the International Society of Sports Nutrition, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 53 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
53citing papers in PubMed, 3 pooled it
8.7field-weighted citation impact, top 1% 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

53 citing papers in PubMed, 3 syntheses or guidelines pooled it, 101 citations in OpenAlex.

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  11. Fluorinated Carnitine Derivatives as Tools to Visualise Carnitine Transport and Metabolism.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2026
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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

3 authors at 3 institutions in 3 countries.

Angelika K SawickaDepartment of Human Physiology, Faculty of Health Sciences, Medical University of Gdansk, 80-210, Gdansk, Poland.
Gianluca RenziUniversity of Camerino, 62032, Camerino, Italy.
Robert A OlekDepartment of Athletics, Strength and Conditioning, Poznan University of Physical Education, Krolowej Jadwigi 27/39, 61-871, Poznan, Poland. robert.olek@aol.com.ORCID http://orcid.org/0000-0002-3714-7386
Gdańsk Medical University · PLHungarian University of Sports Science · HUUniversità di Camerino · IT

Funding

Narodowe Centrum Nauki 2014/15/B/NZ7/00893
6 · The paper itself

Abstract

backgroundL-carnitine (LC) is used as a supplement by recreationally-active, competitive and highly trained athletes. This systematic review aims to evaluate the effect of prolonged LC supplementation on metabolism and metabolic modifications.

methodsA literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from the inception up February 2020. Eligibility criteria included studies on healthy human subjects, treated for at least 12 weeks with LC administered orally, with no drugs or any other multi-ingredient supplements co-ingestion.

resultsThe initial search retrieved 1024 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with healthy human subjects, with supplemented dose ranging from 1 g to 4 g per day for either 12 or 24 weeks. LC supplementation, in combination with carbohydrates (CHO) effectively elevated total carnitine content in skeletal muscle. Twenty-four-weeks of LC supplementation did not affect muscle strength in healthy aged women, but significantly increased muscle mass, improved physical effort tolerance and cognitive function in centenarians. LC supplementation was also noted to induce an increase of fasting plasma trimethylamine-N-oxide (TMAO) levels, which was not associated with modification of determined inflammatory nor oxidative stress markers.

conclusionProlonged LC supplementation in specific conditions may affect physical performance. On the other hand, LC supplementation elevates fasting plasma TMAO, compound supposed to be pro-atherogenic. Therefore, additional studies focusing on long-term supplementation and its longitudinal effect on the cardiovascular system are needed.

Indexed as

Energy MetabolismAge FactorsBody CompositionCarnitineCognitionDietary CarbohydratesDietary SupplementsExerciseExercise ToleranceHumansLipid MetabolismMethylaminesMuscle ProteinsMuscle, SkeletalMuscle StrengthObesityCarnitineDietary CarbohydratesMethylaminesMuscle ProteinstrimethyloxamineAtrogin-1Forkhead box OInsulin-like growth factor-1Mammalian target of rapamycinMuRF-1Protein kinase BTrimethylamine-N-oxide

Identifiers

PMID32958033
PMCPMC7507632
OpenAlexW3087399555

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.