Do you know your vitamin D3 level? My girlfriend had RA went through intravenous treatments which didn't help much. When I finally convinced her to start high dose vitamin D her symptoms stopped and went away.

Come to find out her doctor did do a D test. Her level was 3.

Vitamin D affects all parts of the body including the immune system.

Cholecalciferol and Rheumatoid Arthritis
An Evaluation of High-Dose Vitamin D for Rheumatoid Arthritis
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4089514/

Clinical aspects of vitamin D in the management of rheumatoid arthritis
https://academic.oup.com/rheumatolo...11/1617/1789081
Superiority of a High Loading Dose of Cholecalciferol to Correct Hypovitaminosis D in Patients with Inflammatory/Autoimmune Rheumatic Diseases
https://www.researchgate.net/public...atic_D iseases