Vitamin D 'can lead to better outcomes for obese osteoarthritis patients'

A new study has highlighted the improved outcomes achieved by obese osteoarthritis patients who increase their vitamin D intake.

Carried out by the University of Florida and published in the Clinical Journal of Pain, the study analysed blood samples for vitamin D levels from a racially diverse group of 256 middle-aged and older adults, as part of a larger project to study racial and ethnic differences in pain in individuals with osteoarthritis.

Participants were asked to provide a self-report of knee osteoarthritis pain and completed functional performance tasks such as balance, walking and rising from sitting to standing.

It was shown that of the 126 obese participants, 68 were vitamin D-deficient, while this was true of only 29 of the 130 non-obese participants. It suggests that obesity is significantly associated with clinically relevant vitamin D deficiency.

Moreover, obese individuals who suffered from osteoarthritis and had adequate vitamin D levels were shown to have better functional performance across the various tests than those with insufficient vitamin D.

Lead author Toni Glover, an assistant professor at the University of Florida College of Nursing, said: "Vitamin D is inexpensive, available over-the-counter and toxicity is fairly rare. Older obese patients with chronic pain should discuss their vitamin D status with their primary care provider. If it's low, take a supplement and get judicious sun exposure."

This vitamin can also be found in salmon, tuna, sardines, shrimp, mushrooms and egg yolks, and is stored in the liver and human fat cells. Previous research has shown that the larger amount of fat tissue in obese people can cause vitamin D to be stored, instead of circulated in the body.

A spokesman for Arthritis Research UK said the studies confirmed that vitamin D is often low in people with various types of arthritis and related conditions. "There is now a growing interest in the use of dietary supplements to prevent and treat a wide range of diseases, including osteoarthritis," he added.

The charity is funding a clinical trial of vitamin D supplementation in people with osteoarthritis of the knee. It aims to find out if the supplement can prevent the destruction of cartilage and reduce pain.