Low vitamin K status is associated with osteoarthritis in the hand and knee

Neogi T, Booth SL, Zhang YQ, et al. · Arthritis and Rheumatism

Higher plasma vitamin K was associated with lower prevalence of radiographic hand OA (prevalence ratio falling from 1.0 to 0.7 across quartiles, P=0.005) and knee osteophytes (PR 1.0 to 0.6, P=0.01).

Population

Framingham Offspring Study participants, mean age 65.6 years, 358 women

Intervention

Plasma phylloquinone (vitamin K1) measured; no intervention

Comparator

Highest vs lowest plasma vitamin K

Limitations

Cross-sectional analysis — cannot show causation; measured K1, not K2; vitamin K status tracks overall diet quality (confounding).