Apple Cider Vinegar

There have been reviews of apple cider vinegar on this website.
While many of the folk medicine uses of vinegar are unproven (or were disproved), a few do have a medical research backing them up. Some small studies have hinted that apple cider vinegar could help with several conditions, such as diabetes and obesity.
So what do the editors of WebMD have to say and warn us about the possible side effects of this practice.