Feedback on doctors that sell nutrional supplements

When I lived in Southern California I went to a doctor that I believe is an internist and asthma/allergy specialist. I could barely walk from my bed to the bathroom without resting. I had just lost my job but COBRA'd excellent insurance.

My insurance spent about 60K that year and a half. The doctor ordered an enormous amount of labs and test. All the regular blood work, plus a test on my serotonin level, dopamine level, Spect scans of my brain, Brain MRI, Knee MRI, sleep study etc etc.

When I later moved to the Seattle area, I had the doctor in Southern California teleconference with my new doctor. In the conversation the doctor in Southern California mentioned he was selling over 500K of nutritional supplements a year.

Other doctors I have gone to since look down on doctors who sell nutrional supplements. A relative who is an endicronogist also said it is a conflict of interest.

Since I am going to need pre-op tests and nutritional consulting it seems convenient to go back to the doctor in Southern California. He won't accept Medicare which I have now. But most of the labs would probably be covered anyways.

What are other people's experiences with doctors that sell nutritional supplements?