Urinary citrate level

Urinary citrate levels measure the excretion of citrate—a tricarboxylic acid cycle intermediate—in urine. Citrate acts as the main endogenous inhibitor of kidney stone formation by binding calcium, thereby preventing its crystallization. Low urinary citrate (hypocitraturia) is considered a significant risk factor for calcium nephrolithiasis and can result from metabolic acidosis, potassium deficiency, or disorders of proximal tubular function. Citrate excretion is tightly regulated by acid–base status and dietary intake; low levels warrant investigation for causes such as renal tubular acidosis or chronic kidney disease. Potassium citrate supplementation is used to elevate urinary citrate and prevent stone formation.

Other names

Urinary citric acid excretionCitraturiaUrine citrateUrinary citric acid

Alkali agents (e.g., potassium citrate) increase urinary citrate excretion and alkalinize urine, reducing stone risk. Drugs lowering systemic pH, potassium, or magnesium decrease urine citrate and are to be avoided in stone-formers.