Your QVD file will be an extract of data from your database. If you have a .QVW which you are using to pull the data from the database, this will define the fields and possibly any changes to the field names within the .QVD output file.
If your database changes, you will need to rerun your QVD generator to pick up additional data or, if the field names have changed, amend the list of fields in the 'edit script' of the QVD generator to pick up the new fields or new names. If your output .QVD has changes, this will also require you to change your 'edit script' in your front-end or visualisation ,QVW where you create your charts and tables to pick up the new fields and names.
