Vitamin D supplements linked to less cartilage, joint loss in knee OA
Among patients with knee osteoarthritis, higher intake with both vitamins C and D is associated with less cartilage degeneration, while supplementation with vitamin D alone over 4 years is linked with significantly less progression of knee joint abnormalities, according to data published in Arthritis Care & Research.
“Various vitamin deficiencies have been identified in subjects with OA, including decreased vitamin C and D serum levels,” Gabby B. Joseph, PhD, of the University of California, San Francisco, and colleagues wrote. “One study found that the odds of having hip OA was 1.9 times lower in subjects with recommended or higher vitamin C intake and another study reported that 24% of patients with advanced OA (and upcoming [total knee replacement]) were vitamin D deficient (<40 nmol/L). Thus, understanding the impact of vitamin deficiency on knee joint health, and the value of nutritional supplements to prevent or treat OA is of significant scientific and clinical interest.”
To analyze the links between vitamin C and D supplementation and MRI measures of cartilage composition and joint structure, Joseph and colleagues studied data from the Osteoarthritis Initiative. Joseph and colleagues included 1,785 participants from the initiative with radiographic Kellgren Lawrence knee grades of 0 to 3 in the right knee.
The researchers analyzed vitamin C and D intake, including dietary and supplemental, from baseline using answers in the Block Brief 2000 questionnaire. In addition, they evaluated MRI data using 3T cartilage T2 quantification and semiquantitative joint morphology gradings (WORMS), at baseline and 4 years. To determine the links between baseline vitamin intake and baseline WORMS scores and cartilage T2, the researchers used linear regression.
According to the researchers, higher vitamin C intake was associated with lower average cartilage T2, medial tibia T2 and medial tibia WORMS (coefficient standard range = –0.07 to –0.05). Higher vitamin D intake was associated with a lower cartilage WORMS sum score and medial femur WORMS score (coefficient standard range = –0.24 to –0.09). Regular intake of vitamin D supplements, in doses of 400 IU at least one every week, over a period of 4 years, was associated with significantly less progression of cartilage, meniscus and bone marrow abnormalities (OR range = 0.4 to 0.56).
“Overall, the cross-sectional results showed that some measures of vitamin C and D intake from food and supplements were associated with less cartilage degeneration,” Joseph and colleagues wrote. “While consistent vitamin C supplementation over 4 years did not have a significant association with changes in joint morphology, consistent use of at least 300 IU of vitamin D at least 4-6 days per week) over 4 years was associated with less progression of knee joint abnormalities in the cartilage and bone marrow, and consistent use of at least 400 IU at least 1-3 days per week was beneficial for cartilage, bone as well as meniscus tissues.” – by Jason Laday
Disclosure: The researchers report funding from the NIH.