Nursing at Cal Poly

Hey so I am a freshaman at Cal Poly slo majoring in nutrition and I have just decided that I want to become a nurse. Are school says you can still become a nurse through cal poly since in my major there is a concentration called nutrition science where you can design your schedual to meet pre reqs for your desired health career. I am confused though about what I do after I have completed all my chem, bio and other pre reqs and have graduated. Will I than have to go to community college or another college to get my bsn to become a RN? If I fo go to nusring program at another 4 year college, how hard is it to get in, and will it take me less than 4 years since I will have done all the pre reqs here in cal poly.

And please don't suggest transfering because I love it here at cal poly, and love learning about nutrition, and I also feel a background in nutrition would be valuable as a nurse. I don't mind a few extra years of school.

Thanks!