Arthritis News, Articles, & Information

Vitamin D, which is thought to play a role in coronary heart disease and cancer prevention may also reduce an individuals risk of developing rheumatoid arthritis according to recent evidence.

The largest study on the benefits of vitamin D on rheumatoid arthritis was published in January 2004 in the journal Arthritis and Rheumatism. Researchers in that study analyzed 29,368 women who had participated in the Iowa Womens Health Study. The participants were aged between 55 and 69 and were initially free of rheumatoid arthritis. They were followed over an 11 year study period between 1986 and 1997.

During the study 152 cases of rheumatoid arthritis were identified. The researchers found that those who consumed more than 200 IU of vitamin D each day were 33% less likely to develop rheumatoid arthritis than those who consumed less than 200 IU of vitamin D. The associations were similar for vitamin D intake from both dietary sources and vitamin supplementation and the associations remained after the results were adjusted for other potential risk factors such as BMI and smoking.

The study did not however consider sunlight exposure, which is an important source of vitamin D, which may weaken the significance of the findings.

Vitamin D along with calcium are important for maintaining healthy joints and cartilage and preventing the loss of bone density. Vitamin D is also an immunosuppressant and because rheumatoid arthritis is an autoimmune disorder where an individuals immune system attacks cells in the joints causing inflammation, vitamin D may help prevent this from occurring

The recommended daily intake of vitamin D per day is 200 IU/day for people up to the age of 50 and 400 IU/day for those over the age of 50 however vitamin D is thought to be safe in doses up to 10,000 IU/day. Significant dietary sources of vitamin D include mushrooms (200-1000 IU/serving), cod liver oil, salmon (360 IU/serving), tuna (200 IU/serving), eggs (20 IU/egg), and fortified beverages such as milk and orange juice.