Lock in DB Field after setting it

I am setting up a workflow to make an API call daily and use the data returned to update a user’s fields.

There’s about 8 fields it will update. However, there’s 1 particular field that I only want to be updated on the first API call. I don’t want any future API calls updating that field.

So is there anyway I can like, lock in a field’s data after it’s set? Or any other ideas how I’d do this?

My current solution involves making an additional API call for just that field which won’t recur. But of course that’s an extra API call. Seeing if I can avoid it.