The plasma and urine kinetics of erythritol and the effect of erythritol on plasma glucose and insulin levels were studied in human volunteers administered a single oral dose of 1 g erythritol/kg body wt. The plasma level of erythritol increased during the first 30 to 40 min, reaching a maximum value of approximately 2.2 mg/ml after 90 min. Plasma levels of erythritol then declined gradually to approximately 1.5 to 1.7 mg/ml at the end of the 3-hr sampling period. An average of 30% of the ingested amount of erythritol was excreted unchanged in the urine during the first 3 hr. Total urinary excretion increased to 78% after 24 hr. Renal clearance of erythritol was approximately half that of creatinine, indicating tubular reabsorption of erythritol by the kidney. Mean plasma glucose and insulin levels, measured for up to 3 hr after ingestion, were unaffected by erythritol. The results of this study indicate that erythritol was readily absorbed following oral administration and was excreted unchanged in the urine. Less than 20% of erythritol remained unabsorbed and was available for colonic fermentation and potential production of short-chain fatty acids. Its caloric value was estimated to be < or = 0.4 kcal/g.