Hello @susan333jax
I’ve been taking 200 mcg vitamin K2 MK-7 daily since February with no ill effects. It was a nutritionist recommendation to “help preserve bone in elderly.” I’m eager to see if benefits show up in DEXA testing later this month.
I also increased injectable methotrexate (MTX) dosage for a cPAN vasculitis flare around the same time.

These three “reviews” have sections on vitamin K2 benefits for osteo- and/or rheumatoid arthritis patients.
2017 Vitamins K1 and K2: The Emerging Group of Vitamins Required for Human Health https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5494092/pdf/JNME2017-6254836.pdf
2019 Vitamin K as a Powerful Micronutrient in Aging and Age-Related Diseases: Pros and Cons from Clinical Studies https://www.mdpi.com/1422-0067/20/17/4150
2022 Vitamin K https://www.sciencedirect.com/science/article/pii/S2161831322005476

And here's two vitamin K2 clinical studies that draw from an RA population, most of whom are taking a DMARD. Over 60% of the patients in both studies report taking MTX:

2013 Vitamin K2 administration is associated with decreased disease activity in patients with rheumatoid arthritis https://link.springer.com/content/pdf/10.1007/s10165-012-0789-4.pdf
∘158 female RA patients, 45 mg daily for 3 months
∘over sixty percent of the participants were taking MTX

2015 Menaquinone-7 as a novel pharmacological therapy in the treatment of rheumatoid arthritis: A clinical study https://www.sciencedirect.com/science/article/abs/pii/S0014299915300777
∘84 RA patients, 100 mcg/day for three months
∘over three quarters of the participants were taking MTX

The url @johnbishop shared used an "in vitro" test system of human lymphocytes from rheumatoid arthritis patients. The immunosuppressive effect of combining vitamin K2 and methotrexate is greater than the effect of either agent alone. It is however less than the sum of the individual effects of vitamin K2 and MTX.