Glutamine is a non-essential and conditionally essential amino acid. Our body usually makes sufficient amounts of glutamine 1,2 but in some instances, the body's demand for glutamine increases and it must be obtained from the diet. 1,2 It is also known for playing various other physiological roles in the human body including the facilitation of nitrogen metabolism, balance of acid-base levels in the kidneys. 1. Dietary Reference Intakes: The Essential Guide to Nutrient Requirements, published by the Institute of Medicine's Food and Nutrition Board, currently available online at https://fnic.nal.usda.gov/dietary-guidance/dietary-reference-intakes/dri-reports 2. Jump up^ Lacey, JM; Wilmore, DW (Aug 1990). "Is glutamine a conditionally essential amino acid?". Nutrition Reviews. 48 (8): 297-309. doi:10.1111/j.1753-4887.1990.tb02967.x.