Rh- Superfoods: Salmon, Swordfish and Sardines

It appears that vitamin D deficiency is highly prevalent in patients with RA, and that vitamin D deficiency may be linked to disease severity in RA. As vitamin D deficiency has been linked to diffuse musculoskeletal pain, these results have therapeutic implications. Vitamin D supplementation may be needed both for the prevention of osteoporosis as well as for pain relief in patients with RA.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3539179/

Rh negative individuals and rheumatoid arthritis

Few foods are naturally rich in vitamin D3. The best sources are the flesh of fatty fish and fish liver oils. Smaller amounts are found in egg yolks, cheese, and beef liver. Certain mushrooms contain some vitamin D2; in addition some commercially sold mushrooms contain higher amounts of D2 due to intentionally being exposed to high amounts of ultraviolet light. Many foods and supplements are fortified with vitamin D like dairy products and cereals.

Cod liver oil
Salmon
Swordfish
Tuna fish
Orange juice fortified with vitamin D
Dairy and plant milks fortified with vitamin D
Sardines
Beef liver
Egg yolk
Fortified cereals

https://www.hsph.harvard.edu/nutritionsource/vitamin-d/#:~:text=The%20best%20sources%20are%20the,high%20amounts%20of%20ultraviolet%20light.

Vitamin B12 deficiency

Is a high-protein diet beneficial to Rh negatives?

Mercury in fish