Most information available on getting bloodwork done suggests getting a workup done prior to starting a new supplement regimen to establish your baseline, which acts as a point of reference for further tests. If you would like to be tested for specific vitamins or minerals, make sure to specify those requests to your physician or healthcare professional. Once you've received your results back, your physician or healthcare professional can help you interpret your panel and advise you on what supplements you may need. Thereafter, supplement for 3 - 6 months and then follow up with another bloodwork panel, so you can reevaluate your levels.