At times it is required to first upgrade just the Alpine Linux Package Manager itself to the latest available version, before upgrading any other package. This was the case, for example, when upgrading from a version of Alpine before 2.3.0_rc1. But simply always doing so shouldn't hurt, either:
apk add --upgrade apk-tools
Next, to upgrade all installed packages:
apk upgrade --available
apk update
apk upgrade -s
apk upgrade
apk info -qL PACKAGE
Or:
apk info -L PACKAGE
apk info -qW FILE
Or:
apk info -W FILE
apk info | xargs sudo apk fix