Distilled vinegar: the acid has trials, most of them small

In a meta-analysis of 16 randomized trials with 910 adults, 750 to 3600 mg of acetic acid a day for about 8 weeks lowered fasting glucose by 35.73 mg/dL (95% CI 7.67 to 63.79) in people with type 2 diabetes. Triglycerides fell by 20.51 mg/dL (95% CI 8.04 to 32.98) in adults with overweight who were otherwise healthy. Most of those trials had an unclear or high risk of bias, five did not state the dose, and none measured acetate in the blood. Acetic acid is the part every vinegar shares. FDA guidance describes distilled vinegar as made by fermenting dilute distilled alcohol and expects every vinegar to hold 4 g of acetic acid per 3.4 fl oz (100 mL), in a compliance guide rather than a binding regulation. Beyond the acid the bottle holds very little, with about 6 mg of calcium per 3.5 oz (100 g) in a single USDA legacy record. The trial doses are not a safe intake: undiluted vinegar drinks and vinegar tablets have injured the esophagus in case reports, and no study has tested vinegar together with insulin or other glucose-lowering drugs.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• USDA lists distilled vinegar with only trace minerals per 3.5 oz (100 g), about 6 mg of calcium and 0.5 micrograms of selenium, from a single legacy record with no sample spread. — USDA SR Legacy record Vinegar, distilled Evidence E source
  Calcium 6 mg, selenium 0.5 ug, copper 0.006 mg per 3.5 oz (100 g)
• FDA guidance defines distilled vinegar as vinegar made by acetous fermentation of dilute distilled alcohol and expects every vinegar to contain 4 grams of acetic acid per 3.4 fl oz (100 mL). — vinegar sold in the United States Evidence E source
  Minimum 4 g acetic acid per 3.4 fl oz (100 mL) (4 percent acid strength)

What your body absorbs

• In a crossover trial in 30 healthy people, acetate from 750 mg of acetic acid peaked in blood 15 minutes after a vinegar drink and 30 minutes after capsules. — 30 healthy subjects after an overnight fast, single doses of 750 mg acetic acid as drink or 9 capsules (n = 30) Evidence B source
  Drink peak 15 min, back to baseline at 90 min; capsule peak 30 min, baseline at 120 min
• In a small randomized trial, 1 g of acetic acid as vinegar on a salad cut the blood glucose response to 50 g of bread carbohydrate by 31.4%, while the same vinegar neutralized with baking soda did not, and gastric emptying was unchanged. — 5 healthy subjects for glucose, 4 others for gastric emptying ultrasound, single test meals (n = 5) Evidence B source
  Glucose response -31.4% (P = 0.0228) with acidic vinegar vs neutralized vinegar or blank, no difference in gastric emptying time

What cooking and storage change

• In 13 healthy adults, boiled potatoes stored cold for 24 hours and dressed with 0.99 oz (28 g) of white vinegar had a 43% lower glycemic index and 31% lower insulin index than freshly boiled potatoes. — 13 healthy volunteers, Sweden, single meals with 50 g available carbohydrate in random order (n = 13) Evidence B source
  GI 96 vs 168 and II 128 vs 185 (minus 43% and 31%) for cold potatoes with vinaigrette vs freshly boiled

What it does to your health

• A meta-analysis of 16 trials with 910 adults found that about 750 to 3600 mg of acetic acid a day for around 8 weeks lowered fasting glucose by about 36 mg/dL in type 2 diabetes and triglycerides by about 21 mg/dL in overweight adults. — adults in 16 randomized trials, overweight or obese and with type 2 diabetes, 750 to 3600 mg acetic acid daily, about 8 weeks (n = 910) Evidence A source
  TAG -20.51 mg/dL (95% CI -32.98 to -8.04) overweight/obese; TAG -7.37 mg/dL and FBG -35.73 mg/dL (95% CI -63.79 to -7.67) in type 2 diabetes; no effect on HbA1c, HDL or BMI
• In 16 people with type 2 diabetes, vinegar lowered the 2-hour glucose response to a high glycemic index meal of mashed potatoes from 311 to 181 mmol min/l but did nothing to a low glycemic index meal. — 16 patients with type 2 diabetes split into two matched groups of single test meals (n = 16) Evidence B source
  Glucose iAUC 181 vs 311 mmol min/l (P = 0.04) with a high GI meal, 229 vs 238 (P = 0.56) with a low GI meal

Safety, limits and interactions

• A single case report linked acute pancreatitis in an 84-year-old woman to a newly started apple cider vinegar weight loss supplement, a signal rather than proof. — one 84-year-old woman (n = 1) Evidence D source
  Acute pancreatitis possibly linked to the supplement
• A 15-year-old who drank 3.4 to 5.1 fl oz (100 to 150 mL) of an undiluted fruit vinegar drink every morning for a month developed deep bleeding ulcers along the whole esophagus, which healed within a week of treatment. — one 15-year-old boy, Korea, pomegranate-fermented vinegar beverage (2.7% acidity, pH 2.6) drunk without the 3:1 dilution the maker advised (n = 1) Evidence D source
  Multiple deep longitudinal ulcers with hemorrhage along the entire esophagus; complete mucosal resolution on day 7
• After an apple cider vinegar tablet injured a person's esophagus, tests of 8 tablet brands found wide variation in tablet size, acidity, acid content and label claims. — one reported adverse event and eight commercial apple cider vinegar tablet products, USA (n = 8 products) Evidence D source
  Considerable variability between brands in tablet size, pH, component acid content and label claims

What people believe that the data does not support

• Randomized feeding studies in 16 and 14 young adults found that vinegar reduced appetite mainly because it caused nausea, so the authors judged its promotion as an appetite suppressant inappropriate. — healthy normal weight young adults, two acute randomized crossover studies (n = 30) Evidence B source
  Lower appetite and intake with vinegar, accompanied by significantly higher nausea ratings, largest with the unpalatable drink
• In a small randomized crossover trial in 20 adults without kidney stones, a week of daily apple cider vinegar did not change 24-hour urine citrate, pH or volume, unlike lemon water and coconut water. — 20 non-stone formers, one week per beverage, 6 completed the vinegar arm (n = 20) Evidence B source
  No significant change in urinary citrate, pH or volume with vinegar, lemon water +167.7 mg/24 h citrate
• The EU refused to authorize the health claim that apple cider vinegar helps control and normalize body weight, and no vinegar claim is authorized in the EU register. — EU food labeling Evidence E source
  Claim non-authorized, 0 of 6 vinegar claims authorized

Who this works differently for

• Observational data link vinegar to tooth erosion in children: among 309 matched UK children, those with erosion ate vinegar and fruit more often than caries-active or caries-free children. — 309 age and gender matched UK children with dental erosion, active caries or no caries, structured dietary histories (n = 309) Evidence C source
  Higher fruit and vinegar consumption in the erosion group, no effect size given in the abstract
• In a non-randomized pilot of 10 people with type 1 diabetes and gastroparesis, 2 tbsp (30 ml) of apple cider vinegar a day further slowed gastric emptying, and one patient reported more hypoglycemic episodes. — patients with type 1 diabetes and diabetic gastroparesis, 2 tbsp (30 ml) apple cider vinegar daily for two weeks (n = 10) Evidence C source
  Median gastric emptying rate 17% with vinegar vs 27% with water; one spontaneous report of more frequent hypoglycemia
• A woman who drank about 8.5 fl oz (250 ml) of cider vinegar a day for 6 years was found with unexplained low blood potassium (hypokalemia) of 2.8. — one woman, Austria, about 8.5 fl oz (250 ml) cider vinegar a day diluted in water and as salad dressing, 6 years (n = 1) Evidence D source
  Unexplained hypokalemia of 2.8 (unit and full range not in the text read)

What is still unknown

• The trial base behind vinegar's metabolic claims is thin: in a 16-trial meta-analysis five trials did not state the acetic acid dose and none measured blood acetate. — 16 randomized trials of dietary acetic acid in adults (n = 910) Evidence A source
  5 of 16 trials without a stated dose, 0 with blood acetate, 1 controlling background vinegar intake

The bottom line

The meal studies are small and short. In 5 healthy people, 1 g of acetic acid as vinegar on a salad cut the blood glucose response to bread by 31.4 percent, while the same vinegar neutralized with baking soda did not, and stomach emptying, measured in 4 other people, did not change. In 16 people with type 2 diabetes, vinegar lowered the two hour glucose response to mashed potatoes from 311 to 181 mmol min/l. It made no significant difference to a low glycemic meal (229 against 238). In 13 healthy Swedish adults, potatoes boiled, chilled for 24 hours and dressed with vinaigrette had a glycemic index of 96 against 168 when freshly boiled, and the study could not separate the vinegar from the chilling. Acetate from a single 750 mg dose reached the blood fast in 30 healthy people, peaking 15 minutes after a vinegar drink and 30 minutes after capsules. Two popular uses have been tested and failed. In two crossover studies in young adults of normal weight, vinegar did lower appetite, and the authors traced that mostly to nausea, so they judged selling it as an appetite suppressant inappropriate. A week of daily apple cider vinegar did not significantly change urine citrate, pH or volume in adults without kidney stones, and only 6 people finished that arm. The EU refused a claim that apple cider vinegar helps control body weight. The harms on record come from case reports and small studies, none with distilled vinegar itself. A 15-year-old who drank 3.4 to 5.1 fl oz (100 to 150 mL) of an undiluted fruit vinegar drink every morning for a month developed deep bleeding ulcers along the whole esophagus, which healed within a week of treatment. An apple cider vinegar tablet injured another person's esophagus, and tests of 8 tablet brands found wide differences in size, acidity, acid content and label claims. Among 309 UK children, those with tooth erosion ate vinegar and fruit more often, an association without a dose. In a pilot of 10 people with type 1 diabetes and slow stomach emptying, 2 tbsp (30 ml) of apple cider vinegar a day slowed emptying further, and one person reported more frequent low blood sugar. No study has tested vinegar alongside insulin or glucose-lowering drugs, so whether it adds to their effect is unknown. A woman who drank about 8.5 fl oz (250 ml) of cider vinegar a day for 6 years had unexplained low blood potassium. We found no source on vinegar taken with digoxin or diuretics. Nausea was the main reason appetite fell in the appetite studies. One case report describes acute pancreatitis in an 84-year-old woman soon after she started an apple cider vinegar weight loss supplement, a single case with no cause established.

Sources

1. dvin-r6-10 · food composition table
   Vinegar, distilled, FDC 172237 (sr_legacy): Calcium 6 MG, Selenium 0.5 UG, Copper 0.006 MG per 100 g
   USDA FoodData Central, SR Legacy, FDC 172237 Vinegar, distilled · checked 2026-10-01
2. dvin-r6-11 · agency guidance
   Each of the varieties of vinegar listed below should contain 4 grams of acetic acid per 100 mL.
   US FDA, CPG Sec. 525.825 Vinegar, Definitions · checked 2026-10-01
3. dvin-r6-03 · randomized crossover trial
   In the vinegar drink group, serum acetate concentration increased immediately after intake, peaked at 15 min and returned to baseline at 90 min. That in the vinegar capsule group rose slowly, peaked at 30 min and returned to baseline at 120 min.
   J Nutr Sci Vitaminol (Tokyo), 2010 · checked 2026-10-01
4. dvin-r6-04 · randomized crossover trial
   Similarly, the glucose response was depressed by 31.4% (P = 0.0228) after AcOH+Bread with respect to AcNa + Bread and Blank + Bread. No difference was observed between gastric emptying times after AcOH + Bread and AcNa + Bread.
   Eur J Clin Nutr, 1995 · checked 2026-10-01
5. dvin-r6-05 · randomized crossover meal test
   GI and II of cold potatoes added with vinegar (GI/II=96/128) were significantly reduced by 43 and 31%, respectively, compared with GI/II of freshly boiled potatoes (168/185).
   Eur J Clin Nutr, 2005 · checked 2026-10-01
6. dvin-r6-01 · meta-analysis of RCTs
   Sixteen studies were included, involving 910 participants who consumed between 750 and 3600 mg acetic acid daily in interventions lasting an average of 8 weeks. Dietary acetic acid supplementation resulted in significant reductions in TAG concentrations in overweight and obese but otherwise healthy individuals (mean difference [MD] = -20.51 mg/dL [95% confidence intervals = -32.98, -8.04], P = .001) and people with type 2 diabetes (MD = -7.37 mg/dL [-10.15, -4.59], P < .001). Additionally, acetic acid supplementation significantly reduced FBG levels (MD = -35.73 mg/dL [-63.79, -7.67], P = .01) in subjects with type 2 diabetes compared with placebo and low-dose comparators.
   J Acad Nutr Diet, 2021 · checked 2026-10-01
7. dvin-r6-06 · randomized trial
   In group A, the incremental area under the curve of glucose (GiAUC(120)) was lower after the addition of vinegar (181+/-78 mmol min/l vs 311+/-124 mmol min/l, P=0.04).
   Eur J Clin Nutr, 2010 · checked 2026-10-01
8. dvin-r6-12 · case report
   We discuss an 84-year-old woman with acute pancreatitis possibly linked to a recently introduced weight loss supplement containing apple cider vinegar.
   ACG Case Rep J, 2024 · checked 2026-10-01
9. sf-dvin-hf2-2 · case report
   He had been habitually drinking more than half a cup (100–150 mL) of a pomegranate-fermented vinegar beverage with no sufficient dilution every morning for 1 month. The acidity of this beverage was 2.7% with a pH of 2.6, and it was composed of acetic acid (35%), citric acid (60%), and maleic acid (5%) in the form of organic acids. The manufacturer recommended a 3:1 dilution of water and vinegar before drinking. ... The esophagogastroduodenoscopy showed multiple deep and longitudinal ulcers with concurrent hemorrhage and denudation along the entire esophagus (Fig. 2A).
   Clinical Endoscopy, 2020, 53(3):366-369, Corrosive Esophageal Injury due to a Commercial Vinegar Beverage in an Adolescent · checked 2026-10-08
10. sf-dvin-hf2-3 · case report
    After an adverse event was reported to the authors, eight apple cider vinegar tablet products were tested for pH, component acid content, and microbial growth. Considerable variability was found between the brands in tablet size, pH, component acid content, and label claims.
    Journal of the American Dietetic Association, 2005, 105(7):1141-4, Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products · checked 2026-10-08
11. dvin-r6-07 · randomized crossover trial
    These studies indicate that vinegar ingestion enhances satiety whereas orosensory stimulation alone does not, and that these effects are largely due to poor tolerability following ingestion invoking feelings of nausea. On this basis the promotion of vinegar as a natural appetite suppressant does not seem appropriate.
    Int J Obes (Lond), 2014 · checked 2026-10-01
12. dvin-r6-08 · randomized crossover trial
    ACV did not significantly change 24-h urinary parameters. Coconut water (+ 273.8 mg/24 h, 95% CI 67.9-480 mg/24 h) and lemon water (+ 167.7 mg/24 h, 95% CI 16-319 mg/24 h) were associated with increased urinary citrate.
    Int Urol Nephrol, 2026 · checked 2026-10-01
13. dvin-r6-09 · regulatory register
    POL-HC-6626 Apple cider vinegar Helps control and normalize body weight. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6626, snapshot 2026-09-21 · checked 2026-10-01
14. sf-dvin-hf2-1 · case-control study
    Structured dietary histories were taken from 309 age and gender matched children to determine the type and frequency of intake of acidic foods and drinks, together with any drinking habits that prolonged exposure of the teeth to dietary acids. ... Fruit and vinegar consumption was higher in the erosion group, as was the taking of vitamin C supplements.
    ASDC J Dent Child, 2000 · checked 2026-10-08
15. sf-dvin-hf2-4 · non-randomized crossover pilot trial
    The median value of the GER after the meal including vinegar was 17% (range -55% to 43%, q1 = -9%, q3 = 32%), while the median value of the GER after the reference meal 27% (range -11% to 51%, q1 = 5%, q3 = 41%). ... One of the subjects who already had a slow GER spontaneously reported a higher frequency of hypoglycaemic episodes during the two-week period of drinking apple cider vinegar. ... However, a limitation of this study is that it was not randomized and the subjects were not blinded.
    BMC Gastroenterology, 2007, Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus: a pilot study · checked 2026-10-08
16. sf-dvin-hf2-5 · case report
    unexplained hypokalemia of 2.8 ... the patient had ingested large amounts of cider vinegar regularly for 6 years. She consumed about 250 ml of vinegar per day diluted in water and as salad dressing.
    Nephron, 1998, 79(2):242, Hypokalemia, hyperreninemia and osteoporosis in a patient ingesting large amounts of cider vinegar (Lhotta et al.) · checked 2026-10-08
17. dvin-r6-02 · meta-analysis of RCTs
    Five of the 16 studies did not specify the dose of acetic acid delivered, and no studies measured blood acetate concentrations. Only one study controlled for background acetic acid-rich food consumption during intervention periods. Most studies had an unclear or high risk of bias.
    J Acad Nutr Diet, 2021 · checked 2026-10-01