brace yourself. super newb question...

if you have a pwn'd phone will upgrading to itunes damage anything??? don't know where i got this from, but for some reason i thought i heard this a while back. if not, do i need to avoid updating anything while running a jailbroken phone?

thanks to anyone who can help

btw, i don't think this matters but i have a 3g running a pwn'd 2.0 firm