When do you need arginine?

Arginine is used for synthesis of protein, agmatine, polyamines and creatine [1]. Because kidneys synthesize arginine usually in sufficient amounts in the urea cycle(releasing 2-4g daily), it's normally not necessary to attain it from the diet [1p196;229].

At times, however, arginine can become conditionally essential [1p229]. Such times would include protein malnutrition, excessive ammonia production, excessive lysine intake, burns, infections, peritoneal dialysis, rapid growth, urea synthesis disorders, or in the inflammatory state of sepsis [2]. A deficiency could result in fatty liver, poor wound healing, hair loss, skin rash and constipation [2].

Arginine is changed into nitric oxide causing blood vessel relaxation [2], which can lower blood pressure. Thus, should not be used by a patient with low blood pressure [3]. If suffering of sickle cell disease, arginine can worsen symptoms [3].

One should exercise caution if supplementing with arginine because the amino acid is known to result in anaphylaxis in patients with certain allergies [3]. Those on anticoagulants should note that arginine can increase risk of bleeding [3]. It can increase potassium levels, especially in liver disease patients [3]. And the amino acid can increase blood sugar levels so may be contraindicated for patients who are trying to control blood sugar levels [3].

Reference List
1. Gropper SS, Smith JL, Groff JL. Advanced Nutrition and Human Metabolism. Belmont, CA: Thomson Wadsworth, 2009.
2. Mayo Clinic. "Arginine (L-arginine): Background." Available at: http://www.mayoclinic.com/health/l-arginine/NS_patient-arginine.
3. Mayo Clinic. "Arginine (L-arginine): Safety." Available at: http://www.mayoclinic.com/health/l-arginine/NS_patient-arginine/DSECTION=safety.