The undergraduate calendar's not loading right now, or else I would check for you. Check the undergraduate calendar for HTH SCI 2L03 when you can (under the specific course code, not the program) and see what the prerequisites are. SOLAR should also tell you which prerequisite you don't have when you try to add the course and it rejects you.
If you finally get to the course and it's full, but it's required for your program (and it somehow turns out this is just a SOLAR error, and there are no prerequisites) contact an advisor in the Health Science department (go on to the mac website and find the department page for Health Sci - there will be a list of contacts there, somewhere). They will probably give you a seat.
If you are currently taking the prerequisite right now, contact that same person in the Health Sci department and ask for a prerequisite waiver so that you can sign up for the course, at least.
And if this is a SOLAR error or something email/CALL (which is better) the Associate Dean's office of your faculty and explain your situation to them.
Hope that helps!