PRAGUE — Low dietary vitamin D intake is linked to an increased rate of knee osteoarthritis, Dr. Nigel K. Arden reported at the 2006 World Congress on Osteoarthritis.
The association was seen in tibiofemoral but not patellofemoral disease, and in women but not in men, Dr. Arden said at the meeting, which was sponsored by the Osteoarthritis Research Society International.
“This effect was driven by dietary intake, not supplementation,” he added, noting that the mean dietary vitamin D intake in the 957 British patients, measured by food frequency questionnaires, was 3.2 mcg per day. A total of 39% of the cohort took vitamin D supplements, boosting their daily intake to 4.3 mcg per day, which is still “woefully below what's recommended,” said Dr. Arden of the University of Southampton (England).
The study randomized patients from the larger Hertfordshire Cohort Study, a multiple outcome study which included patients born in Hertfordshire, England, from 1931 to 1939 and still living there. It noted a 10.5% rate of symptomatic, radiographic tibiofemoral OA in the cohort at baseline; this was negatively associated with dietary vitamin D intake.
While vitamin D insufficiency is known to increase with age, it is expected to increase more significantly with the growing emphasis on sun avoidance and the use of sunscreen, Dr. Arden said.