Vitamin D Deficiency and Rheumatoid Arthritis Link
Could a vitamin D deficiency contribute to rheumatoid arthritis? If you are a woman who lives in the northeastern United States, it is a good possibility, according to a new study from Boston University School of Public Health. States in northern latitudes get less sunlight, which can result in a vitamin D deficiency.
Previous research has indicated an association between vitamin D deficiency and rheumatoid arthritis, as well as other autoimmune disorders. A recent report from Tufts Medical Center noted that “vitamin D has been shown to modulate the immune system, and its deficiency has been linked to the development of several autoimmune disorders” and that disorders such as rheumatoid arthritis has been associated “to some extent to vitamin D deficiency.”
Similarly, a new study published in Rheumatology International showed that while serum vitamin D levels in people with rheumatoid arthritis were similar to those in healthy individuals, the levels of the vitamin decreased significantly in line with disease activity and the patient’s decreasing ability to function.
In the Boston University study, Dr. Veronica Vieira, MS, DSc, associate professor of environmental health, and her colleagues examined data from the Nurses’ Health Study, the “grandmother” of women’s health studies and the single largest cohort study of women. Specifically, they looked at residential addresses, health outcomes, and behavioral risk factors for 461 women who had rheumatoid arthritis and compared them with a control group of 9,220. They found that women who lived in states like Vermont, New Hampshire, and southern Maine were more likely to have been given a diagnosis of rheumatoid arthritis than women living in more southern latitudes.
Vieira noted that other studies had observed a geographic relationship between northern latitudes and other autoimmune diseases, such as multiple sclerosis and Crohn’s disease that “may be mediated by reduced vitamin D from decreased solar exposure and the immune effects of vitamin D deficiency.”
Rheumatoid arthritis is a chronic disease in which the lining, or synovium, of the joints becomes inflamed. This inflammation can lead to long-term joint damage, stiffness, chronic pain, and disability. Rheumatoid arthritis can extend beyond the joints and affect other organs as well. Approximately 1.3 million Americans have rheumatoid arthritis, and although the cause is unknown and there is no cure, it often can be managed through medication, exercise, and lifestyle modifications.
Given the results of this and other recent studies indicating a link between vitamin D deficiency and rheumatoid arthritis, there is a great deal of interest in pursuing further research, especially because vitamin D is a nonprescription, inexpensive, easily accessible substance that could be used to help prevent and treat this autoimmune disease.
Boston University Medical Center
Nurses Health Study
Pelajo CF et al. Vitamin D and autoimmune rheumatologic disorders. Autoimmunity Reviews 2010 Feb 8.
Turhanogllu AD et al. Rheumatology International 2010 Mar. 19