Recommendation Letters for EB1A

I already have some recommendation letters from my NIW petition. I want to file EB1A now. Can I use these letters? I searched online and it seems that these two categories have very different criteria and standards. So maybe I need to obtain new letters for EB1A? Any advice?

to blackduck528:

I think you can probably still use them for your EB1A case. But you need to consult with your EB1A attorney as to how much of those letters can be apply to the EB1A case.