Vinegar (VIN) ingestion at mealtime reduces postprandial glycemia and may benefit individuals with diabetes; hence, the medicinal use of VIN has increased in recent years. This study examined the safety and tolerance of medicinally ingested VIN in type 2 diabetics. Participants (n = 27) were stratified by gender, age, and body mass and randomized into three groups: commercial VIN pills (the reference treatment [REF] (30 mg of acetic acid daily), pickles (PCK) (approximately 1,400 mg of acetic acid daily), or VIN (2,800 mg of acetic acid daily). Participants continued their normal eating habits during the 12-week trial. At baseline and weeks 6 and 12, fasting blood and urine samples were collected, and adverse changes in bowel movements, frequency of burping or flatulence, and episodes of acid reflux were recorded. Reporting frequency for adverse events did not vary significantly by group during the trial; however, 50-56% of PCK and VIN participants reported at least one treatment-emergent adverse event at week 6 as compared to 11% of REF participants (P = .110). Urinary pH was significantly reduced in VIN participants at week 12 as compared to the other groups (-9% vs. +3% and +2% for the PCK and REF groups, respectively, P = .023). At week 6 there was a tendency for aspartate aminotransferase concentrations to increase in the VIN group as compared to the other groups (+17% vs. +8% and -8% for VIN, PCK, and REF, respectively; P = .090). These data indicate that chronic VIN ingestion may influence hepatic function and metabolic pathways aside from glucose metabolism.