The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study.
Level 3 - non-randomized controlled study
Prospective longitudinal cohort study assessing structural knee MRI outcomes over 3 years.
PubMed 25528106 · doi:10.1016/j.joca.2014.12.008
What was done
Researchers evaluated cross-sectional and longitudinal associations between vitamin K status and MRI-defined knee osteoarthritis (OA) features using data from the Health, Aging and Body Composition Study. Plasma phylloquinone (PK, vitamin K1) and dephosphorylated-uncarboxylated matrix-gla protein ((dp)ucMGP) were measured in 791 community-dwelling older adults (mean age 74 ± 3 years, 67% female) who underwent bilateral knee MRIs. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for OA presence and 3-year progression were calculated using generalized estimating equations adjusting for age, sex, body mass index, triglycerides, and other confounders.
What was found
Longitudinally over 3 years, participants with very low plasma PK (<0.2 nM) had higher odds of articular cartilage damage progression (OR 1.7, 95% CI: 1.0–3.0) and meniscus damage progression (OR 2.6, 95% CI: 1.3–5.2) compared to those with sufficient PK (≥1.0 nM). Cross-sectionally, highest versus lowest quartile of plasma (dp)ucMGP was associated with higher odds of meniscus damage (OR 1.6, 95% CI: 1.1–2.3), osteophytes (OR 1.7, 95% CI: 1.1–2.5), bone marrow lesions (OR 1.9, 95% CI: 1.3–2.8), and subarticular cysts (OR 1.5, 95% CI: 1.0–2.1), but (dp)ucMGP was not associated with longitudinal progression.
Why it matters
This study links low circulating vitamin K to specific MRI-identified joint tissue lesions and shows that very low phylloquinone predicts worsening structural knee damage over time, supporting a protective role for vitamin K in joint integrity.
Limits
The observational design cannot establish causality or exclude residual confounding by overall nutritional status or physical activity. While low PK predicted structural progression, the functional marker (dp)ucMGP did not predict longitudinal progression. Findings from this older cohort (mean age 74) may not generalize to younger populations.
Cited by
- supports Without adequate vitamin K2, calcium is deposited in blood vessels and forms bone spurs rather than being incorporated into bones.