AUGUSTA, Maine (AP) Maine Gov. Paul LePage has vetoed a bill to require insurance carriers to provide coverage for services provided by naturopathic doctors.

Naturopathy’s an alternative medical system that focuses on things like diet, herbs and vitamins instead of pharmaceuticals. The Maine Association of Naturopathic Doctors used social media on Monday to urge residents to request an override of the veto.

LePage’s veto message says the bill would restrict insurance carriers from constructing provider networks that “deliver quality and cost-effective services.”

Some mainstream medical groups oppose granting naturopaths access to insurance, or licensing them to practice at all. The Massachusetts Medical Society issued a statement last year opposing the licensure of naturopaths in that state, saying the field “lacks rigorous medical training and standards of care.”

Naturopaths have license access in Maine.