By David Liu, PHD

Taking vitamin K2 supplements or eating vitamin K2 rich foods may help decrease the activity of rheumatoid arthritis, according to a Japanese study in Modern Rheumatology.

Vitamin K2 has been known to induce bone mineralization and apoptosis of osteoclasts and also apoptosis of rheumatoid arthritis synovial cells among other things. 

The current study led by K. Ebina of  Osaka University Graduate School of Medicine in Osaka and colleagues found that female patients with rheumatoid arthritis who received vitamin k2 shots reduced the serum levels of certain biomarkers that indicate the activity of inflammation associated with rheumatoid arthritis.

Of 158 female rheumatoid arthritis patients at a mean age of 62.5 years who had not been treated with drugs like warfarin, biologics and teriparatide prior to entering the study, 70 were given 45 mg of vitamin K2 per day via intravenous injection.

The patients who were treated with vitamin k2 had greater than 4.5 ng of undercarboxylated osteocalcin in their blood or had decreased bone mineral density at the beginning of the study although they received other anti-osteoporosis prescription drugs.  In a longitudinal study, 52 patients were additionally treated with vitamin k2 for three months without changing their medication treatments.

Compared to the controls, those using vitamin K2 showed lower serum c-reactive protein, MMP-3 and DAS28-CRP.

C-Reactive Protein is an indicator of rheumatoid arthritis and many other inflammatory diseases including heart disease.  MMP-3 (Stromelysin) is found high in patients with rheumatoid arthritis and DAS28-CRP is often used to assess the disease activity of rheumatoid arthritis.

In the longitudinal study, patients who were treated with vitamin k2 experienced a significant decrease in serum CRP, MMP-3, and DAS28-CRP.

The study suggests that vitamin K2 may help improve disease activity in addition to osteoporosis in patients with rheumatoid arthritis.