A family of Microsoft word processing software products for creating web, email, and print documents.
For frames within the document's main StoryRange, you can just use
Dim f As Frame
For Each f In ActiveDocument.Frames
f.Range.Fields.Update
Next f
If there are frames anchored in headers, though, you'll have to handle those separately. This is similar to how you handled fields in the headers themselves.
Dim f As Frame
Dim h As HeaderFooter
For Each f In ActiveDocument.Frames
f.Range.Fields.Update
Next f
For Each h In ActiveDocument.Sections.Last.Headers
For Each f In h.Range.Frames
f.Range.Fields.Update
Next f
Next h
Gratuitous hint: Sections.Last is the same as Sections(ActiveDocument.Sections.Count).