Depending on how much vinegar you drink, the vinegar might do nothing or make you nauseous, but it can be lethal in extremely high doses. There are several different types of vinegar, and some of them are actually beneficial in small amounts. However, large amounts of vinegar increase the amount of acid in the stomach, causing nausea or vomiting, and lowering pH levels.
Having a few tablespoons of vinegar in water or with salad is not harmful to the body. However, the main ingredient in vinegar is acetic acid, which is harmful to humans in large doses. Because vinegar is 10 percent acetic acid, a half gallon is lethal to most humans. Large amounts of vinegar can also burn the esophagus and cause a variety of issues stemming from low pH levels. These include hypokalemia, hyperreninemia, vertigo, vomiting, constipation and gastrointestinal distress. Because most of these symptoms only occur when consuming large amounts of vinegar, it is a good idea to limit the daily intake of vinegar to a small amount of a few tablespoons. Most medical studies suggest taking no more than two tablespoons of vinegar before a meal. It is always best to consult a doctor before taking vinegar as a supplement.