Wait, how is it that your status says you're a medical student but then you haven't even started college yet? Isn't that like some type of violation of TOS? You should probably change that.
Anyway, to you original question. No, it doesn't matter what your major is as long as you have a high GPA, you do your premed prereqs and do well on the MCATs. Now if you're wondering what classes will help more when you do get into med school that would be biochem, anatomy (if offered) and maybe physiology depending on how it's taught. Personally, I think bio majors have it slightly easier in med school than non-science majors. Now before anyone starts arguing with me and accusing me of flaming: yes, I know everyone's gonna have to relearn all the material and they do teach you everything you need to know and yes non-science kids do just as well as the science kids in med school. HOWEVER, having seen the material before makes it easier to make connections in between the different topics introduced. You're not spending your time just trying to memorize the details you can start integrating the information. And yes, I do hear a lot of the non-science kids complaining they're feeling overwhelmed having to learn this stuff in only several weeks.