heya

so it's the doc not the neuro saying no to more nutrient tests?
either way i can hook you up with some study abstracts so you can try to convince him that the tests are worthwhile.
make sure you get your own copy of the results. don't let them just tell you everything is 'normal'. that's not good enough. everyone with ms is 'normal'. we just hang out in the sick people's part of the 'normal' range. not where you want to be!
other than that your option is to pay to see a naturopath. they can requisition the tests too. the difference is, if the requisition comes from the doc then some is covered by OHIP. if the requisition comes from the naturopath, the patient has to pay for all the tests.
if you have to go the naturopath route, once you have the tests then you have to try to avoid the upsell re coming in to the office for repeated b12 injections etc, when the science has demonstrated that sublingual b12 is just as effective as injection. a little bit of buyer beware.
once you have the results, see what the naturopath has to say but definitely bring the results here. my naturopath never heard of the kind of approach i'm finding useful (eg ignore 'normal' levels and focus on 'healthy/optimal' levels)
anyway that advice re coverage only applies to my particular health care jurisdiction, ontario canada.