Change e-mail address in I-tunes
I have changed my e-mail address on the apple ID website and have been able to change it for ICloud. My e-mail address (ID) has not changed for I-tunes and therefore, I can't install updates. ??
iPad, iOS 7.1
Try tapping on your id at the bottom of the Featured tab in the App Store app and log out of the account and then log back in with the updated version of your account so as to 'refresh' the account on it, and see if you can then download updates to your apps with it