Shea MK, Loeser RF, McAlindon TE, Houston DK, Kritchevsky SB, Booth SL. Association of Vitamin K Status Combined With Vitamin D Status and Lower-Extremity Function: A Prospective Analysis of Two Knee Osteoarthritis Cohorts. Arthritis Care Res (Hoboken). 2018 08; 70(8):1150-1159.