Fish Oil, Vitamin D Supplements Fail To Alleviate Chronic Knee Pain: Study

According to the findings of a new study, fish oil and vitamin D supplements are often not helpful in alleviating symptoms of osteoarthritis, raising questions about wide-spread use of the products.

Contrary to many marketing claims, vitamin D and omega-3 supplements do not help with long-term knee pain, stiffness, or function, according to findings published this month by researchers from Brigham and Women’s Hospital, in the journal Arthritis and Rheumatology.

Omega-3 fatty acids have anti-inflammatory effects and vitamin D promotes bone restoration and bone strength. The two have been promoted as possible treatments for knee pain from osteoarthritis, which is common among the adult population, because they help with muscle strength and bone restoration. Fish oil can also aid with cartilage loss.

The new research indicates neither is linked to significant improvements in pain, function or mobility for osteoarthritis. The findings follow other studies which have shown conflicting results regarding the effects of supplements like vitamin D and omega-3 fatty acids.

Researchers conducted a large randomized, double-blind, clinical trial of more than 25,000 adults enrolled in the VITamin D and OmegA-3 TriaL (VITAL). This included nearly 1,400 participants who returned at least one knee pain questionnaire and received 2,000 IU/day of vitamin D and 1 g/day of omega-3 fatty acids beginning in 2011.

The data indicates taking omega-3 supplements or taking vitamin D supplements failed to alleviate chronic knee pain in older adults.

Participants took daily dietary supplements of vitamin D3 or omega-3 fatty acids, however neither helped reduce the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of the illnesses.

Pain scores on the 100-point Western Ontario and McMaster Universities Arthritis (WOMAC) Index among patients receiving omega-3 fatty acids or placebos were 36.5 and 35.4 at baseline. At the final follow up visit, pain scores were 33.6 among patients in the fish oil group and 33.7 in the placebo group.

After five years follow up, WOMAC pain scores were decreased in the two groups, but by only a small amount. There was no statistically significant difference in pain scores between the vitamin D and placebo groups.

In fact, there was no significant differences in pain scores between the two groups at any time point, researchers determined.

One-quarter of older adults experience knee pain, usually related to osteoarthritis. Current treatment options include exercise, weight loss, and pain medication, which are often associated with adverse effects.

Research strongly suggests these nutritional supplements may reduce risk for cancer, but evidence for alleviating osteoarthritis are lacking.

Researchers say identifying safe and effective therapies which reduce pain could vastly improve management of chronic knee pain. However, their findings appear to exclude vitamin D supplements and fish oil from the list of potential effective treatments.