Contribution of Dietary Oxalate to Urinary Oxalate in Health and Disease

With typical, moderate levels of oxalate consumption, about one half of urinary oxalate derives from the diet in healthy people without gastrointestinal disease. Thus far, nine foods have been shown to increase urinary oxalate. These foods are spinach, rhubarb, beets, chocolate, nuts, tea, wheat bran, strawberries, and soy foods, which should be limited in the diets of patients susceptible to kidney stone formation. In addition, including more calcium-rich foods with meals can reduce urinary oxalate excretion as dietary calcium appears to bind oxalate in the gut lumen reducing its absorption. Thus, evidence suggests that limiting dietary intake of high oxalate foods and increasing calcium intake with meals may reduce urinary oxalate and may decrease renal stone formation.