Acetic acid is the substance that gives vinegar its distinctive smell and sour taste. A synthetic cousin of acetic acid, called ethylenediamine-tetraacetic acid (EDTA), attracts some dissolved metals. It is used in cases of lead, mercury, or iron poisoning to pull these metals out of the bloodstream. A dubious practice called chelation therapy involves repeated administration of EDTA. Chelation therapy is hyped as a way to clean out the arteries by dissolving cholesterol-filled plaque. This is based on wishful thinking, not science.
Apple cider vinegar is a terrific ingredient in foods, sauces, and dressings. It isn't medicine. Taking too much can lower blood potassium levels and may not be good for your bones. If you choose to take a tablespoon or so a day, rinse out your mouth afterward -- straight apple cider vinegar can erode the enamel on your teeth.