Vitamin D Ineffective for Knee Osteoarthritis

By Pat Anson, Editor

Recent studies have suggested that Vitamin D supplements may help reduce pain from fibromyalgia, arthritis and other chronic conditions.

But the “sunshine vitamin” did not relieve pain or stop cartilage loss in patients with knee osteoarthritis, according to new research published in JAMA.

Osteoarthritis is a joint disorder that leads to thinning of cartilage and progressive joint damage. Knee osteoarthritis (OA) is very common and affects over 250 million people worldwide. Nearly 40 percent of Americans over the age of 45 have some degree of knee OA.

Over 400 people with knee OA and low serum levels of Vitamin D participated in the placebo controlled study in Australia and Tasmania. They were divided into two groups; with one receiving Vitamin D supplements and the other a placebo.

Over the course of the two-year study, knee pain, stiffness and physical function were measured with the WOMAC pain scale and MRI scans were used to monitor cartilage volume, defects and bone marrow lesions.  

While the supplements did increase Vitamin D blood levels, they did not reduce knee pain. MRI’s also showed no significant differences in cartilage between the two groups.

“Vitamin D supplementation, when compared with placebo, did not result in significant differences in change in MRI-measured tibial cartilage volume or change in WOMAC knee pain score over 2 years. These findings do not support the use of vitamin D supplementation for preventing tibial cartilage loss or improving WOMAC knee pain among patients with knee osteoarthritis,” said lead author Changhai Ding, MD, of the University of Tasmania.

Vitamin D helps control levels of calcium and phosphate in the body and is essential for the formation of strong bones and teeth. Vitamin D also modulates cell growth, improves neuromuscular and immune function, and reduces inflammation

Vitamin D deficiency – a condition known as hypovitaminosis D -- is caused by poor nutritional intake of Vitamin D, inadequate sunlight or conditions that limit Vitamin D absorption. The most severe type of hypovitaminosis D causes general body pain, especially in the shoulder, rib cage, lumbar and pelvic regions.

Researchers at National Taiwan University Hospital recently found a “positive crude association” between fibromyalgia and hypovitaminosis D.  According to the Vitamin D Council, low levels of Vitamin D could be the result of fibromyalgia, rather than the cause of the disease.

Sources of Vitamin D include oily fish and eggs, but it can be difficult to get enough through diet alone. Ultraviolet rays in sunlight are the principal source of Vitamin D for most people.