ReviewAmino acids2021
Tolerable amounts of amino acids for human supplementation: summary and lessons from published peer-reviewed studies.
Review in Amino acids, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers, 2 of them syntheses that pooled 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.
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.
Who cites it
22 citing papers in PubMed, 2 syntheses or guidelines pooled it, 41 citations in OpenAlex.
- Safety assessment of L-ornithine oral intake in healthy subjects: a systematic review.Amino acids · 2025Pooled it
- Safety assessment of L-Arg oral intake in healthy subjects: a systematic review of randomized control trials.Amino acids · 2023Pooled it
- Evaluation of the Safety and Tolerability of L-Tyrosine Supplementation in Healthy Adult Men: A Randomized Crossover Trial.Nutrients · 2026Trial
- Evaluation of safe utilization of L-threonine for supplementation in healthy adults: a randomized double blind controlled trial.Amino acids · 2025Trial
- Toxicological Risk Assessment of Urban Motorcycle Noise Using WHO Night Noise Guidelines.Journal of urban health : bulletin of the New York Academy of Medicine · 2026Article
- Untangling amino acid metabolism in renal diseases: mechanisms, dysregulation, and critical gaps.Clinical kidney journal · 2026Review
- Relevance and Safe Utilization of Amino Acids in Supplements for Human Nutrition: Lessons from Clinical and Preclinical Studies.Nutrients · 2026Review
- Assessing gut microbial provisioning of essential amino acids to host in a mouse model with reconstituted gut microbiomes.Communications biology · 2025Article
- Multi-Omics and -Organ Insights into Energy Metabolic Adaptations in Early Sepsis Onset.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2025Article
- Off-target depletion of plasma tryptophan by allosteric inhibitors of BCKDK.Molecular metabolism · 2025Article
- L-Phenylalanine promotes liver steatosis by inhibiting BNIP3-mediated mitophagy.Molecular medicine (Cambridge, Mass.) · 2025Article
- Dose-dependent L-arginine cardiotoxicity in diabetic cardiomyopathy: Mechanisms and clinical implications.World journal of diabetes · 2025Article
- Enhancing the Quality of Ready-to-Eat Trout Burger Patties: Investigating the Combination of Modified Atmosphere Packaging and Microbial Transglutaminase Enzyme.Food science & nutrition · 2024Article
- An Update of the Promise of Glycine Supplementation for Enhancing Physical Performance and Recovery.Sports (Basel, Switzerland) · 2024Review
- Alkaptonuria.Nature reviews. Disease primers · 2024Review
- Tolerable Upper Intake Level for Individual Amino Acids in Humans: A Narrative Review of Recent Clinical Studies.Advances in nutrition (Bethesda, Md.) · 2023Review
- Subchronic tolerance trials of graded oral supplementation with ornithine hydrochloride or citrulline in healthy adults.Amino acids · 2023Article
- Estimating the Mass of Food Components Necessary for the Utilization of Free Radical Particles in the Human Body.International journal of environmental research and public health · 2022Article
- Analytical Chemistry of Impurities in Amino Acids Used as Nutrients: Recommendations for Regulatory Risk Management.Nutrients · 2022Review
- Dietary supplementation with monosodium glutamate enhances milk production by lactating sows and the growth of suckling piglets.Amino acids · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 5 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Amino acid supplementation may be indicated to correct for insufficient amino acid intake in healthy individuals, and in specific physiological or pathophysiological situations. However, there is a concern to not supplement beyond the tolerable upper intake level (UL) by determining parameters of no-observed-adverse-effect level (NOAEL) or lowest-observed-adverse-effect level (LOAEL) for each amino acid. Since the NOAEL and LOAEL values are at least one order of magnitude different when comparing the values obtained in rats and humans, the aim of this review is to evaluate to what extent the amino acid UL measured in the rat model, when referenced to the dietary usual consumption (UC) and dietary requirement (RQ) for indispensable amino acids, may be used as an approximation of the UL in humans. This review then compares the ratios of the NOAEL or LOAEL over UC and RQ in the rat model with the same ratios calculated in humans for the nine amino acids (arginine, serine, glycine, histidine, leucine, lysine, methionine, phenylalanine, and tryptophan) for which this comparison can be done. From the calculations made, it appears that for these 9 amino acids, the calculated ratios for rats and humans, although rather different for several amino acids, remains for all of them in the same order of magnitude. For tryptophan, tyrosine, and valine, the ratios calculated in rats are markedly different according to the sex of animals, raising the view that it may be also the case in humans.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.