I called the school and asked them about this. FAFSA recommends including it because some healthcare schools require parental information for internal reasons, and also so they can give need-based scholarships to the most disadvantaged. However, UTHSCSA does not require it of anyone. I called to make sure, and ended up submitting my FAFSA without any parental information. However, UTHSCSA also said that if you do include it, it won't affect the federal aid you receive whatsoever.
so moral of the story: you can include it or not, up to you, it won't make a difference either way. including it definitely won't hurt you.