Vitamin D may help prevent arthritis of the knee

Having a low blood level of vitamin D may lead to painful arthritis of the knee according to researchers from the Menzies Research Institute in Tasmania, Australia. Low Vitamin D is associated with a loss of cartilage in the knee joint of older individuals according to the report. Lead author of the study Dr. Changhai Ding states in an interview “Cartilage loss is the hallmark of osteoarthritis.” By the time patients reach the point of needing knee replacement, 60% of the cartilage has been lost, he said.

However, “achieving vitamin D sufficiency in osteoarthritis patients could significantly delay total knee replacement,” states Dr Ding. In their study, Ding and colleagues found “osteoarthritis patients with Vitamin D sufficiency have approximately 1.5 percent less loss of knee cartilage per year than patients with Vitamin D deficiency.” The investigators measured levels of Vitamin D in blood samples and knee cartilage volume on X-rays from 880 men and women aged 51 to 79. The team then took similar measurements again almost 3 years later in 353 of the study participants. Overall, 58 % of these subjects showed changes in knee cartilage indicating worsening osteoarthritis between the first and second measurements, and half reported knee pain. Both at the beginning of the study enrollment and at follow up, men and women with vitamin D deficiency had lower knee cartilage volume and were more likely to experience knee pain. Ding's team concludes that Vitamin D plays an important role in cartilage changes, and that Vitamin D deficiency may predict knee cartilage loss over time. The study is published in the May 2009 issue of the journal Arthritis & Rheumatism.