Study: Vitamin D May Help Older Women Avoid Rheumatoid Arthritis

Older women who take in higher amounts of vitamin D are significantly less likely to develop rheumatoid arthritis than those who take in low amounts, according to a study reported in the January issue of Arthritis & Rheumatism.

The researchers analyzed data from a study of 29,368 women between the ages of 55 and 69 years who did not have rheumatoid arthritis at the beginning of the study in 1986. The participants filled out a food frequency questionnaire that included use of supplemental vitamin D. The participants were divided into three groups based on the amount of vitamin D they took in: lowest to highest.

After 11 years, the researchers found that 152 of the study participants had developed rheumatoid arthritis. The group having the greatest intake of vitamin D had 33 percent less risk of developing rheumatoid arthritis than the group with the lowest intake.

Researcher Kenneth G. Saag, an associate professor at the University of Alabama at Birmingham, said the study provides provocative and preliminary evidence that sufficient intake of vitamin D may prevent rheumatoid arthritis among older women.

"It offers yet another reason why older adults should get adequate vitamin D," Saag told Medical Week. "Since dietary sources of vitamin D are scarce and sun exposure is particularly difficult for many elders in the winter, a multi-vitamin providing 400 internatinal units per day of vitamin D is a reasonable option for many."

Although the study did not address just why vitamin D can counteract rheumatoid arthritis, Saag said previous animal and in vitro studies have indicated that Vitamin D has immunomodulatory properties that could influence the onset of rheumatoid arthritis.

Saag said more work is needed to both address this question as well as to confirm the findings of the study that he and his colleagues conducted.

Other sources: Arthritis and Rheumatism 50:1:72-77