My immediate thought is Vitamin B6 50mg thrice a day - but my second thought is suggest you have a look at
http://www.breastcancercare.org.uk/community/forums/xeloda-capecitabine-your-top-tips-please . This thread is what is says on the packet and is quite active, and has lots of good info in it. Third thought - thinking on my feet here!! - is a dose reduction - I started on 2500, but struggled on cycle 1 with extreme tiredness, now on 1950 and so much better, and I'm told I'm on 75% and it's still effective down to 50%!
But best suggestion is use the existing thread - than any advice you get will benefit someone else more readily!!
Nina