Seniors having minimal Vitamin D and Vitamin K walked faster
Sufficient vitamin K status combined with sufficient vitamin D status is associated with better lower extremity function: a prospective analysis of two knee osteoarthritis cohorts
Arthritis Care and Research, online: 17 October 2017. DOI: 10.1002/acr.23451
M. Kyla Shea, Richard F. Loeser, Timothy E. McAlindon, Denise K. Houston, Stephen B. Kritchevsky, Sarah L. Booth
Objective
Vitamins K and D are important for the function of vitamin K-dependent proteins in joint tissues. It is unclear if these nutrients are mutually important to functional outcomes related to knee osteoarthritis (OA). We evaluated the association of vitamin K and D sufficiency with lower-extremity function in the Health, Aging Body Composition Knee OA Sub-study (Health ABC) and conducted a replication analysis in an independent cohort, the Osteoarthritis Initiative (OAI).
Methods
In Health ABC (60% female, 75±3 years) baseline nutrient status was measured using circulating vitamin K and 25(OH)D. Lower-extremity function was assessed using the short physical performance battery (SPPB) and usual 20-meter gait speed. In the OAI (58% female, 61±9 years), baseline nutrient intake was estimated by food frequency questionnaire. Lower-extremity function was assessed using usual 20-meter gait speed and chair stand completion time. Multivariate mixed models were used to evaluate the association of vitamin K and D status and intake with lower-extremity function over 4-5 years.
Results
Health ABC participants with sufficient plasma vitamin K (≥1.0 nmol/L) and serum 25(OH)D (≥50 nmol/L ) generally had better SPPB scores and faster usual gait speed over follow-up (p≤0.002). In the OAI, sufficient vitamin K and vitamin D intake combined was associated with overall faster usual gait speed and chair stand completion time over follow-up (p≤0.029).
Conclusion
Sufficient vitamin K status combined with sufficient vitamin D status was associated with better lower-extremity function in two knee OA cohorts. These findings merit confirmation in vitamin K and D co-supplementation trials.