It depends if they teach you a "science" course, or, more of an a healthcare, anthro, type course. Science letters from from teachers of BCPM courses. That is the general rule, but some schools may overlook it.
I imagine that if it's from a biostatistics or epidimiology prof, especiallt if you did a masters project or research with them it will be fine. I would ask individual schools though. But then again, if stats and epi count as undergrad science classes, why wouldn't they count in grad school.