Glutamine: Food Sources & Daily Intake

Table of Contents

1. How to Read These Tables
2. Recommended Intakes & Upper Limits
3. Bioavailability & Absorption
4. Cooking & Storage
5. Vegetarian & Vegan Sources
6. Who Needs to Pay Attention
7. Key Research Papers
8. Connections
9. Featured Videos

How to Read These Tables

• Reported together with glutamic acid. Glutamine and glutamic acid are chemically almost identical, and the standard laboratory method (acid hydrolysis) converts glutamine into glutamate before it is measured. Food databases therefore report a single combined figure that covers both — there is no widely available number for glutamine on its own. Read the values below as “glutamine + glutamic acid,” a reliable guide to which foods are richest in glutamine.
• Grams per 100 g, not %DV. There is no U.S. Food and Drug Administration Daily Value for individual amino acids, so this table reports the absolute grams per 100 g of food and ranks foods by that combined glutamine + glutamic-acid total. A typical serving is shown beside each food.
• Conditionally essential. Your body normally makes plenty of glutamine, so most people never need to think about it. It moves onto the “essential” list only under heavy physical stress — major illness, surgery, burns, sepsis or very hard training — when the gut and immune system burn through it faster than the body can resupply.

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Recommended Intakes & Upper Limits

Glutamine has no Daily Value: the U.S. food-label rules (21 CFR 101.9) set none for it, and the green and yellow marks in the food table above only rank each food against the richest food listed. The table below summarizes its status.

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Bioavailability & Absorption

Glutamine from food is well absorbed as part of dietary protein, but most of it never reaches the bloodstream intact: the cells lining the intestine use glutamine as their primary fuel and consume a large share of it on the spot — one of the reasons glutamine is so important to gut health. What matters for nutrition is simply eating adequate total protein; glutamine comes along automatically because it is one of the most plentiful amino acids in protein. Because the body also synthesizes glutamine on demand (chiefly in muscle), blood levels are tightly regulated and food is a top-up rather than the sole source.

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Cooking & Storage

Glutamine is stable to ordinary cooking as part of food protein, and cooking actually makes that protein easier to digest. Worth noting: isolated free glutamine (as in supplements) is heat- and moisture-sensitive and can degrade, but the protein-bound glutamine in everyday foods like meat, cheese, eggs and beans is robust and needs no special handling. Long, gentle simmering — as in a bone or meat broth — releases free amino acids including glutamine into the liquid, which is why brothy, slow-cooked dishes are a traditional, gut-friendly source.

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Vegetarian & Vegan Sources

Glutamine is easy to get on a plant-based diet because it is one of the most abundant amino acids in plant protein. In USDA figures for glutamine plus glutamic acid per 100 g, the strongest plant sources are pumpkin seeds (6.1 g), sunflower seeds (5.6 g) and peanuts (5.4 g), followed by cooked chickpeas (1.6 g), white beans (1.5 g) and lentils (1.4 g). Cabbage, often described as a classic glutamine source, has 0.29 g per 100 g raw and spinach 0.34 g, which puts both among the weakest plant sources by weight. For those who include them, whole-milk dairy and eggs are excellent and concentrated sources. Eating enough total protein from a variety of legumes, seeds and vegetables across the day supplies all the glutamine a healthy body needs — no supplement required.

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Who Needs to Pay Attention

Dietary glutamine deficiency does not occur in healthy people eating enough protein, because the body makes its own. The situation changes under severe catabolic stress — major burns, trauma, sepsis, major surgery or critical illness — when muscle glutamine stores can be depleted faster than they are replaced; this is the setting where clinicians sometimes provide supplemental glutamine, and where most of the research has focused. In one large trial in this setting (REDOXS, published in the New England Journal of Medicine in 2013), 1,223 critically ill adults with multiorgan failure on mechanical ventilation received glutamine, antioxidants, both, or placebo; in-hospital and 6-month mortality were significantly higher among those given glutamine, and the authors concluded that glutamine was associated with an increase in mortality among critically ill patients with multiorgan failure. Some athletes and people with gut conditions also take glutamine supplements, though evidence for benefit in otherwise-healthy people is mixed. For the general public, glutamine comes with adequate quality protein; isolated glutamine supplements are a clinical or sports tool, not an everyday dietary need.

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Key Research Papers

1. NIH MedlinePlus — Amino acids
2. National Academies — Dietary Reference Intakes: Protein and Amino Acids (2005), Chapter 10
3. Heyland D, Muscedere J, Wischmeyer PE, et al. A randomized trial of glutamine and antioxidants in critically ill patients. New England Journal of Medicine. 2013;368(16):1489–1497. — PubMed PMID: 23594003
4. PubMed — glutamine metabolism, gut and immune function
5. PubMed — glutamine supplementation in critical illness

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Connections

• All Amino Acids
• Glutamine (Main Page)
• Glutamine Benefits
• Glutamine History
• Glutamic Acid
• Arginine
• Glycine
• Bone Broth
• How the Body Makes Its Own Glutamine

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