We assume we can and should trust our doctors – as it should be. We go to him or her for life impacting advice and treatment. So what if your doctor suggests you take vitamins or nutritional supplements s/he conveniently has for sale in the office? Should you take get bait?
The American Medical Association frowns on the ethics of doctors selling supplements. For one thing, doctors are not trained nutrition professionals. They study a perfunctory numbers of hours in nutrition sciences. A registered dietitian or dietetic technician studies nutrition science and has more education and experience than an MD, unless s/he has specifically and intentionally studied it in his/her training.
Doctors can diagnose, through blood work and symptoms, nutritional deficiencies and may prescribe medications or supplements a patient can purchase at the pharmacy. But never should s/he offer them for sale in the office.
When there is a profit motive, which is the only reason a physician is selling vitamins and supplements, one must question his/her ethics.
See this short video link.