STOP Eating These 7 Foods if You Have Arthritis (& What to Eat Instead)

Berg distinguishes rheumatoid arthritis as an autoimmune condition where the immune system attacks joints; he explains that vitamin D “puts the fire out” by shifting the immune balance away from the pro-inflammatory side. For this effect, doses must be well above the typical supplemental range. He notes that 20,000 IU is a bare minimum for RA, with 30,000–40,000 IU more likely to achieve a therapeutic response. For osteoarthritis and general joint pain, he pushes even higher—suggesting aiming for 70–80 ng/mL blood levels, which may require 60,000–80,000 IU. He stresses that vitamin D is one of the best anti-inflammatories for knees, lower back, and any joint, and that deficiency sends inflammatory signals “way up.” To safely handle these doses, he insists on adding magnesium (prevents calcification and supports D metabolism), zinc, and vitamin K2 (routes calcium to bones, not soft tissues).

Berg explains that deep within cartilage cells, the endoplasmic reticulum folds proteins and stores calcium. In studying arthritis, he repeatedly saw that ER stress originates the cascade of inflammatory events even before mitochondrial stress. He emphasizes that this is the very beginning of the breakdown: if something disrupts the ER, the entire repair and maintenance machinery for the joint collapses, leading to inflammation and calcification. He connects this later to bile salts that specifically target ER stress, reframing arthritis as a failure of this cellular factory.

Berg was puzzled by finding bile salt receptors on cartilage cells. After hours of research, he found two types of bile: primary (liver) and secondary (microbe-modified). Secondary bile salts travel through the blood and attach to chondrocyte receptors, reducing inflammation and protecting the joint. This explains his clinical observation that patients who had their gallbladder removed or took antibiotics almost always developed arthritis—they lost the ability to produce sufficient secondary bile. The finding reframes arthritis as partly a bile-deficiency disease originating from gut dysbiosis.

When Berg researched TUDCA, he found it reduces ER stress, which he had just identified as the origin of arthritic inflammation. He explains that TUDCA is not just a general anti-inflammatory but specifically relieves stress on the protein-folding machinery in chondrocytes. This action shuts down the signaling molecules that drive arthritis, making it more targeted than typical supplements. He ties this back to the earlier bile-receptor discovery, showing that restoring bile signaling—especially with TUDCA—can protect the joint at a cellular level.