Can Vitamin D Prevent Arthritis?

What if you could take a pill that would stop you from ever developing rheumatoid arthritis or osteoarthritis? Research suggests there may be such a pill—and it's widely available and easy to obtain. In fact, your local supermarket no doubt has a bottle of it on a shelf right now. What is this miracle drug? Vitamin D.

Vitamin D, of course, does not have to come in pill form. Our bodies manufacture Vitamin D when we spend time in the sun, and there's a small handful of foods that contain significant levels of it. But most Americans have levels of Vitamin D that are too low—up to 60 percent of us, by expert estimates. Many of us don't spend a lot of time outdoors (or if we do, we slather ourselves with sunscreen, which doesn't allow the sun's rays to penetrate our skin and enable the production of D) or consume enough liver, fish, eggs, or fortified milk to get the D we need. The solution? A daily Vitamin D supplement.

Experts have long known that Vitamin D is important to bone health because it enables our bodies to absorb and use the calcium we consume. But now there's evidence that Vitamin D might have a lot to do with the health of our joints as well. This is because D is an active hormone in addition to being a crucial bodily nutrient. This hormone binds to tissue receptors in arthritis-prone joints and keeps the tissues healthy and functional. Vitamin D also keeps our immune systems humming and helps fight infections.

Scientists looked at data on more than 29,000 women involved in the Iowa Women's Health Study who had no history of rheumatoid arthritis. The women filled out a detailed food questionnaire that included everything they consumed, including Vitamin D supplements. Over a period of 11 years, a handful of cases of rheumatoid arthritis were diagnosed in the women. The scientists noted that the higher the levels of Vitamin D consumed by the women, based on their self-reported intake of foods and supplements, the less likely they were to be diagnosed with arthritis. Conversely, people with various forms of arthritis may be even more likely than the general population to be deficient in Vitamin D. Research presented at the 2008 European League Against Rheumatism meeting showed that almost three-quarters of patients who showed up at a rheumatology clinic had subpar levels of Vitamin D.

A simple blood test can determine whether you have adequate Vitamin D in your system. If you don't, consider taking a supplement. You may also want to spend small amounts of time outside in the sun without sunscreen (if you and your dermatologist are comfortable with that) and bumping up your consumption of D-fortified foods.



Johns Hopkins,
National Institutes of Health,