I am discussing with my physician, via e-mail, what tests I want do at my next appointment. She has minimal knowledge of ME/CFS. She suggested a B12 blood panel. I take my B12 (methyl and adenosyl) sublingually. Will that show up as expected in a blood test? I see in my notes that a the only thing a serum B12 test is good for is suggesting a functional block if it is high. I have no insurance, so this is self-pay. Is it worth the cost?