virtualbox.org

I lost my vdi file but I have all the snapshots can I recreate the vdi file from snapshots?

Short answer is no. Restore for your backup is the only way.

Snapshot feature/facility creates only a delta update to the 'base' virtual disk, not an image replacement. The deltas are not stand-alone images; they must be applied to the 'base' image in the hierarchy that they were created. The deltas may be merged with the 'base' image (time consuming if many deltas} or the Virtual Machine may be cloned, creating a new 'base' image.