Hello, Welcome to Just Answer and thanks for your question. All medical professionals are not all against alternative medicine. Scientifically proven alternative medicine is welcomed. We even have a web site within the National Institutes of Health http://nccam.nih.gov/ that examines evidence for using non-traditional medicine.
However, there are some so-called "pure" things that are not compatible with prescribed medication, or someone's health condition. After all, arsenic is "pure" as well. There may be a very good scientific reason why your rheumatologist wants you off certain supplements. Why don't you ask him?