Dietary oxalate and kidney stone formation

T Mitchell, P Kumar, T Reddy… - American Journal …, 2019 - journals.physiology.org
T Mitchell, P Kumar, T Reddy, KD Wood, J Knight, DG Assimos, RP Holmes
American Journal of Physiology-Renal Physiology, 2019journals.physiology.org
Dietary oxalate is plant-derived and may be a component of vegetables, nuts, fruits, and
grains. In normal individuals, approximately half of urinary oxalate is derived from the diet
and half from endogenous synthesis. The amount of oxalate excreted in urine plays an
important role in calcium oxalate stone formation. Large epidemiological cohort studies have
demonstrated that urinary oxalate excretion is a continuous variable when indexed to stone
risk. Thus, individuals with oxalate excretions> 25 mg/day may benefit from a reduction of …
Dietary oxalate is plant-derived and may be a component of vegetables, nuts, fruits, and grains. In normal individuals, approximately half of urinary oxalate is derived from the diet and half from endogenous synthesis. The amount of oxalate excreted in urine plays an important role in calcium oxalate stone formation. Large epidemiological cohort studies have demonstrated that urinary oxalate excretion is a continuous variable when indexed to stone risk. Thus, individuals with oxalate excretions >25 mg/day may benefit from a reduction of urinary oxalate output. The 24-h urine assessment may miss periods of transient surges in urinary oxalate excretion, which may promote stone growth and is a limitation of this analysis. In this review we describe the impact of dietary oxalate and its contribution to stone growth. To limit calcium oxalate stone growth, we advocate that patients maintain appropriate hydration, avoid oxalate-rich foods, and consume an adequate amount of calcium.
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