I don't know about the urine, but with your stools you should get that checked into. It could be an infection, but the only one who would know for sure would be your doctor. I have also had some real dark black stools. I've had abdominal pain on and off for 2 years. I was told that I had ovarian cysts (2 1/2 years ago) and was put on the pill but the pain continues. Now, all this time later, I'm starting to pass the dark stools. I called the doctor today and I have an appt next week. However, if I pass one more dark stool or have any abdominal pain they want me to come in ASAP to see the nurse practitioner. So,
I would advise you to do the same. I would mention the vitamin to them when you call, it could be that. Either way, get to the doc!