Genetically predicted vitamin K levels and risk of osteoarthritis: Mendelian randomization study

Zhao SS, Bovijn J, Hughes DM, et al. · Seminars in Arthritis and Rheumatism

The causal test, and it is null: genetically predicted vitamin K was not associated with osteoarthritis overall (OR 0.98 per unit increase, 95% CI 0.96-1.01), nor with knee (0.98), hip (0.97), spine (0.97), hand (0.97) or joint replacement (0.96), and sensitivity analyses agreed.

Population

Up to 826,690 individuals in the largest osteoarthritis genome-wide association study, with vitamin K instrumented from a GWAS of 2,138 people

Intervention

Genetically predicted circulating vitamin K1 level

Comparator

Genetically lower vitamin K

Limitations

The genetic instrument comes from only 2,138 people and explains a small share of variance, so a modest true effect could be missed; it models lifelong small differences in circulating K1, not supplementation with MK-7; the authors call for larger genetic and interventional studies.