About half of all people with rheumatoid arthritis use natural supplements, such as fish oil, glucosamine, chondroitin and vinegar. A study published in Arthritis Care & Research (July 2018) found that most dont tell their doctors. The researchers analyzed results from 23 studies and found that 47 percent of people with rheumatoid arthritis used natural supplements that were not vitamins or minerals. They were usually taken along with prescribed medication for rheumatoid arthritis. Forty-seven percent of people found the supplements to be effective, and 13 percent reported adverse side effects. Only 30 percent of them informed their physicians they were taking supplements. Its important to discuss everything you take with your doctor. Even something that is natural may have side effects or harmful interactions with drugs.