One would think that since apple cider vinegar is acid it would not be good to ingest if you have an acid problem yet rheumatoid arthritis is a build up of uric acid and apple cider vinegar brakes up the uric acid in joints and they disapated and leave the body. The same is true of kidney stones, apple cider vinegar and also red clover tea brakes down the stones which are also made up of uric acid and they are easier to pass.