yea i hear ya. oh, canada.
one option could be to pay for time with an ND. in ontario, an ND can write a test req, but the province won't cover the visit or the ND-ordered bloodwork. in that circumstance, i just paid for the time and the lab work, while having to resist the fairly strong pressure from the ND to buy her products and ongoing services.
http://www.cand.ca/Find_an_ND.findnd.0.html
another option might be to ask the doc for a referral to a nutrition specialist that might be more inclined to write you a nutritional bloodwork requisition. if you let it be known that you'll be getting that test one way or another, the doc might just write you the requisition, or at a minimum give you the referral.
you could also show the doc some related research to help back up your request:
Nutrition in primary care: Current practices, attitudes, and barriers
http://www.cfp.ca/content/56/3/e109.full.pdf
"Findings from this study suggest that physicians recognize the importance of dietary intervention and demonstrate a willingness to provide nutrition counseling. However, inadequate training, time, and compensation; insufficient use of dietitian services; and a lack of evidence-based interventions remain obstacles in the primary care setting.
Initiatives to reduce barriers to preventive counseling and further research around nutrition-related interventions in the primary care setting are needed to mitigate the ever growing burden of preventable chronic diseases."