Glutamine is known to be depleted in certain types of physiological stress such as burns, major trauma, and cancers that consume available intra-cellular glutamine stores more rapidly than skeletal muscle can generate it, leading to increased muscle wasting.
During physical activity, serum glutamine is consumed for longer endurance events (2+ hours); some evidence exists that chronic endurance exercise reduced glutamine levels to affect immune cell function and proliferation.
Glutamine depletion or deficiency is rare, as glutamine can be made endogenously and is ubiquitous in the food supply from both plant and animal sources.
Some studies suggest an increase in intestinal permeability when intestinal epithelial cells lack sufficient glutamine, as well as insufficient availability for leukocyte function.
There is currently no established RDA, AI, or UL for glutamine. Glutamine is typically sold as l-glutamine and doses have been studied in humans ranging from 500 mg/day – 50g/day. Higher doses (>10 g/day) are commonly used in the treatment of intestinal barrier permeability.
Supplementation of glutamine has not been shown to enhance muscle growth in healthy individuals.
Typically an increase in serum insulin results after consumption of glutamine due to increased conversion to glucose. This may impact individuals with insulin resistance. Glutamine supplementation is also potentially beneficial to improve mental focus and concentration, as well as curbing cravings for sugar and alcohol.
In some individuals, glutamine is converted more efficiently to glutamate, which can lead to a neuro-excitatory state, increased anxiety, tension headaches/migraines, and even tachycardia. If any of these symptoms occur after consuming glutamine, discontinue supplementation and discuss with your provider.
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Correlation between WBC ("Cellular") and serum levels:
WBC - deficient and...
Serum levels normal/excess:
Short term status of micronutrients is optiomal, but cellular absorption may be a problem.
Possible interventions:
- Increase dietary intake of nutrient
- increase supplementation dosage
- consider status of synergistic nutrients for cellular absorption
- consider levels of oxidative stress on nutrient depletion
- consider follow up testing to identify the source of malabsorption
Serum levels deficient:
Short term and long term status of micronutrients is not optimal, suggesting low dietary intake and both intestinal and cellular malabsorption as possible causes.
Possible interventions:
- Increase dietary intake of nutrient
- increase supplementation dosage
- medications may have an effect on depletion
- consider follow up testing to identify the source of malabsorption
- Glutamine is a conditionally essential amino acid (conditional mainly during times of disease or muscle wasting, such HIV/AIDS, cancer, or severe infections).
- In the intestinal lining, glutamine is the preferred source of fuel for intestinal epithelial cells and the main energy source for leukocytes (immune cells).
- Other important functions of glutamine include: transporting nitrogen between cells, acting as a precursor to glutathione production, acting as a precursor to nucleotides (for DNA and RNA synthesis), participating in gluconeogenesis in the absence of adequate carbohydrate intake, blunting the rise of blood glucose after consuming carbohydrate-rich meals, and regulating intestinal tight junctions.
Very good sources of glutamine include: whey, casein, milk, white rice, corn, and tofu.
Good sources of glutamine include: meat and eggs.
Glutamine (WBC)
