- Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) ( 2005 ) /10 Protein and Amino Acids National Academic Press
- Glycine PubChem
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- List of foods high and low in glycine US Department of Agriculture
- Glycine WebMD
- de Koning TJ et al, 1998, Beneficial effects of L-serine and glycine in the management of seizures in 3-phosphoglycerate dehydrogenase deficiency PubMed
- Zhong Z et al, 2003, L-Glycine: a novel antiinflammatory, immunomodulatory, and cytoprotective agent PubMed
- Patra FC et al, 1984, In search of a super solution: controlled trial of glycine-glucose oral rehydration solution in infantile diarrhoea PubMed
- Pizarro D et al, 1988, Comparison of efficacy of a glucose/glycine/glycylglycine electrolyte solution versus the standard WHO/ORS in diarrheic dehydrated children PubMed
- Heresco-Levy U et al, 1999, Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia PubMed
- Steed DL et al, 1995, Promotion and acceleration of diabetic ulcer healing by arginine-glycine-aspartic acid (RGD) peptide matrix. RGD Study Group PubMed
- Gusev EI et al, 2000, Neuroprotective effects of glycine for therapy of acute ischaemic stroke PubMed
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- van Vliet D et al, 2014, Single amino acid supplementation in aminoacidopathies: a systematic review PubMed Central
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What is glycine?
Glycine is a conditionally essential amino acid, which can be produced in your body from other amino acids, but in certain circumstances, such as young age or heavy illness, you may need to obtain additional amounts from food to be healthy .
Glycine abbreviation (symbol): Gly
Glycine Functions in the Human Body
Glycine is [2,13]:
- A building block of proteins
- An inhibitory neurotransmitter
- A glucogenic amino acid — it can be converted into glucose
- A precursor of hemoglobin
Foods High in Glycine
- ANIMAL FOODS: meat, fish, cheese 
- PLANT FOODS: legumes 
Foods low in glycine: fruits, vegetables 
Glycine as a Food Additive
Glycine obtained from animal gelatin may be added to certain foods as a bread enhancer. It can be produced from animal gelatin or artificially synthesized . In the European Union it is labeled as the E-number E640.
Nonprescription (over-the-counter) L-glycine supplements are available as capsules or creams.
Glycine Health Benefits
L-glycine supplements are POSSIBLY EFFECTIVE in:
- Treatment of diabetic leg ulcers (when used as a arginine-aspartic acid-glycine cream) [5,11]
- Reducing complications of ischemic stroke [5,12]
- Improvement of symptoms of the hereditary metabolic disorder isovaleric acidemia 
There is INSUFFICIENT EVIDENCE about the effectiveness of glycine supplements in prevention or treatment of arthritis, benign prostatic hypertrophy, cancer, acute diarrhea in infants (when added to oral rehydration solution) [8,9], gastric ulcers, inflammation , phosphoglycerate dehydrogenase (3-PGDH) deficiency  or schizophrenia , or in improving memory, immunity or wound healing .
L-glycine supplements are PROBABLY INEFFECTIVE in the treatment of propionic acidemia  or in improving exercise performance .
Glycine Safety: Side Effects, Toxicity
Glycine seems to be SAFE for most people when taken by mouth or applied to the skin .
Side effects of oral l-glycine supplements may include nausea, stomach upset, vomiting and drowsiness .
Pregnant and breastfeeding women should avoid glycine supplements .
Glycine supplements might decrease the effectiveness of clozapine (a drug to treat schizophrenia) .
Nonketotic Hyperglycinemia (Glycine Encephalopathy)
Nonketotic hyperglycinemia (glycine encephalopathy) is a hereditary disorder in which a lack of glycine cleavage enzyme result in a build up of glycine in the blood, urine and brain .
Symptoms develop shortly after birth and include feeding difficulties, vomiting, small head size, seizures, low or high muscle tonus and severe mental retardation .
Treatment includes a low-protein diet, sodium benzoate, arginine and dextromethorphane . Most of the affected infants die within a year .