Vitamin D Intake and Magnetic Resonance Parameters for Knee Osteoarthritis: Data from the Osteoarthritis Initiative.

PURPOSE: There is evidence that vitamin D may play a role in the osteoarthritis (OA) pathogenesis, but the few data available are limited to X-rays and clinical findings. The aim of this study was to investigate whether a higher intake of vitamin D was associated with a better architecture of the cartilage of the knee, assessed with magnetic resonance (MRI), in a large cohort from North America.

METHODS: 783 participants (59.8% females; mean age: 62.3 years) with an MRI assessment from the Osteoarthritis Initiative were included. Vitamin D dietary intake was calculated as the sum of food and oral supplementation. A coronal 3D FLASH with Water Excitation MR sequence of the right knees was used. The strength of the association between dietary vitamin D intake and knee MRI parameters was investigated through an adjusted linear regression analysis, reported as standardized betas with 95% confidence intervals (CIs).

RESULTS: Using a linear regression analysis, adjusted for ten potential confounders, higher vitamin D intake (reported as an increase in one standard deviation, = 250 IU) corresponded to significantly higher values of mean cartilage thickness and volume of cartilage at medial tibia, volume of cartilage and mean cartilage thickness at central lateral femur, volume of cartilage and mean cartilage thickness at central medial femur, and volume of cartilage and mean cartilage thickness at central medial tibial-femoral compartment.

CONCLUSIONS: Higher vitamin D intake is associated with a significantly better architecture of the cartilage of the knee, also independently taking in account from several potential confounders.