Vinegar has been used as an herbal remedy in the United States since the 18th century. The typical dose is between 1 and 3 teaspoons taken up to three times a day, usually mixed in a glass of water. The safety and effectiveness of ingesting large amounts of vinegar hasn't been studied very much, so speak with your doctor before adding vinegar to your daily routine.
Risk of Gastrointestinal Issues
Because of its acidity, vinegar can make heartburn worse or cause you to become nauseous. According to a review article published in "Medscape General Medicine" in 2006, drinking vinegar straight has resulted in injuries to the esophagus due to its acidity, but this is a rare adverse effect. Taking vinegar as a supplement isn't recommended for people with indigestion or ulcers, or for those who have a narrow esophagus or experience difficulty swallowing.
Damage to Teeth
The acidity of vinegar can damage your teeth by eroding the enamel, which in turn can cause further damage, such as cavities. This side effect is most likely to occur if you regularly drink large amounts of straight vinegar, such as a glass a day. Mixing vinegar with water and drinking it with a straw will limit the potential for causing damage to your teeth.
Potential Medication Interactions
Vinegar in amounts above those typically found in food may interact with certain medications, making adverse reactions more likely. If you take a blood thinner or a diuretic, or you are on medication for diabetes, avoid vinegar supplements altogether, or speak with your doctor about whether it would be safe for you to use vinegar as an alternative remedy.
Interference with Potassium Levels
Although rare, drinking large amounts of vinegar could interfere with your potassium levels, causing them to be too low. There is at least one report of this happening to a woman who drank about a cup of vinegar every day for six years, according to the article in "Medscape General Medicine." Your body may excrete extra potassium due to the process required to digest the vinegar. Low potassium levels can cause fatigue, constipation, muscle damage or an irregular heartbeat.