I asked my doctor about getting my levels checked in regards to vitamins, testosterone, etc. She somewhat rudely brushed it off. Is there a good way to ask about this or should I seek out a specialist on my own?
You might want to find a new doctor. The primary care doctors I've had in my life run blood tests for things like vitamin levels (especially B12 and D) annually.
You can just order bloodwork online with no interaction from a doctor and go to a local lab testing corp to get the blood drawn. This is assuming you're in America.
e.g. privatemdlabs.com (I'm not recommending that site, just giving it as an example, though I have used them in the past and everything worked as expected).