tRefer to this thread:
ManBearDude's post has a link to what schools have what requirements. The ones that do not require a DO letter are pretty much fine with an MD letter. Any and every LoR question you could possibly have has been cut every which way in that thread though, give it a look. I would definitely shadow a DO if at all possible though, so you can at least comment on your exposure to the profession.
You need a physician letter, MD or DO for most osteopathic schools. Other than that you're good.t
for MD schools, i think that it is absolutely okay to not have a LOR from a physician as a result of shadowing. so DO schools not only prefer a shadowing letter, but a DO letter as well?
i have 2 science professor, 2 humanities professor, and 1 volunteer coordinator, plus my composite committee letter.