[decimon]

Does this mean if you’re D deficient you’re more likely to have arthritis?

I don't believe the researchers are clear as to cause or effect. They do see a correlation.

In this case they indicate a desire to test whether increased vitamin D supplementation helps correct RA. Otherwise, I guess, they would have to follow peoples' vitamin D levels for decades to get a good idea if low levels of vitamin D cause RA. And just a good idea because other factors would have to be considered.

IOW, I don't know.

[Fantasywriter]

Thank you. I’m not good at deciphering articles like this (not enough patience?) but that was a very clear and concise answer. I really appreciate it!