Renal effects of short-term ketone monoester supplementation in healthy adults: A randomized, placebo-controlled study.

Recent studies suggest potential benefits of ketosis. However, research is lacking on its effects on renal physiology. This study aimed to investigate the renal effects of short-term exogenous ketosis in healthy adults, focusing on glomerular function and electrolyte handling. In a double-blind, placebo-controlled, randomized crossover trial, 15 healthy participants received ketone monoester (KME) or placebo three times daily for 5 days under a standardized diet, separated by a 2-week washout. On the fifth day of each intervention, participants collected a 24-h urine sample. The following day, glomerular filtration rate (GFR) was assessed with 99mTechnetium-diethylene-triamine-pentaacetate (Tc-99-DTPA) clearance, and urinary electrolyte excretion was measured. Thirteen participants completed both treatment periods. Compared with placebo, KME treatment acutely increased GFR by 6.0 mL/min (p = 0.002) and sodium excretion increased by 69 μmol/min (p < 0.0001), while potassium excretion decreased (-31 μmol/min; p < 0.0001). Electrolyte excretion measured in 24-h urine remained unchanged. In conclusion, short-term KME supplementation was associated with acute increases in measured GFR and urinary sodium excretion, while reducing urinary potassium excretion in healthy adults. No changes in electrolyte excretion were detectable in the 24-h urine, indicating that renal effects are not sustained over the full collection period.