Yesterday I posted more or less the exact same message on the yahoo urine group! No reply from them yet. I hadn't though of a connection to vitamins.....interesing! I wondered if it was crystallised blood.
Mine were diamond shaped and very small, about a millimetre in length. Also they weren't there when I first saved the urine (or at least I'm sure I would have noticed them), but when I looked at it yesterday (after a week) it was full of the red particles.....strange! So I dont' know how they just 'appeared' over the week.