The most important thing to learn in any math class IMHO is to learn how to think critically, logically, and analytically. I find that doing math proofs for various stuff in topics such as Calculus has helped me become more logical in my thinking. I even learned how to prove things in different ways. It does take lots of patience, careful analysis, and logical thinking. Wait a second... aren't those qualities I'd want my doctor to have?
Regarding the actual math, I think high level statistics is useful in what you want. Calculus is great, but statistics seems more applicable in the field. This is just my opinion, however, and I am not in the field you described.
I did a little internet search and found this link. I think it's a good article.