Does it actually say you must take this kind of document with you or merely recommend that you do? I would imagine they could come in handy for certain situations. If you ever need credit in NZ a clean bill of financial health from the UK could open doors for you.

I know you can view your Medical Records, but not sure if they would photocopy them for you if requested. If you have any medical history of note, it?s always useful for a new doctor to have background information and also for you to refresh your memory about your own medical issues if asked.