Rheumatoid arthritis linked to vitamin D deficiency, researchers findSaturday, May 01, 2010 by: Sherry Baker, Health Sciences Editor
Rheumatoid arthritis (RA) is an autoimmune disease that causes pain, swelling, stiffness and loss of function in the joints. Unlike osteoarthritis, the common arthritis that develops from wear and tear on joints and usually develops only as people age, RA can affect the young and old. The disease can cause enormous suffering -- it may attack the eyes, mouth and lungs as well as joints. According to the National Institutes of Health, there's no known cause for RA and treatments include steroids and other drugs that can have serious side effects.
The new research, which was just published online in the journal Environmental Health Perspectives, found that women in states like Vermont, New Hampshire and southern Maine were more likely to report being diagnosed with RA.
Dr. Veronica Vieira, DSc, associate professor of BUSPH environmental health, headed the study using a technique called spatial analysis. Her research team used data from the Nurses' Health Study, a long-term study of U.S. female nurses. They noted where the women lived, their health status and behavioral risk factors for various diseases during the years from 1988 and 2002; the RA findings were based on 461 women who developed RA, compared to a control group of 9,220.
Bottom line: women living at northern latitudes and receiving less sunlight were at risk of vitamin D deficiency and these were the women who had the greatest incidence of RA. What's more, the risk increased even more if women had been living in the north since the beginning of the study in l988.
The researchers noted that vitamin D deficiency has previously been associated with a variety of other autoimmune diseases. "A geographic association with northern latitudes has also been observed for multiple sclerosis and Crohn's disease, other autoimmune diseases that may be mediated by reduced vitamin D from decreased solar exposure and the immune effects of vitamin D deficiency," the authors wrote.
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