Excess of vitamin C may worsen arthritis pain

According to findings from a study involving guinea pigs, prolonged exposure to high doses of vitamin C seems to make osteoarthritis worse. This suggests that people should not exceed the recommended dietary allowance for vitamin C.

Previous short-term studies have indicated that vitamin C might be protective against osteoarthritis, but long-term treatment with vitamin C has not been studied, the researchers note in the medical journal Arthritis & Rheumatism.

Dr. Virginia B. Kraus from Duke University Medical Center in Durham, North Carolina, and colleagues investigated the effects of 8 months' exposure to low, medium, and high doses of vitamin C on the development of knee arthritis in guinea pigs.

The low dose was the equivalent of the amount needed to prevent scurvy, the medium dose represented that obtained by a person consuming five fruits and vegetables daily, and the high dose to match that shown in a previous study to slow the progression of arthritis in guinea pigs, reports reuters.co.uk

According to forbes.com "Everybody needs vitamin C in their diet, but taking supplements beyond the recommended daily allowance is probably inadvisable" when it comes to fighting arthritis, said Dr. Virginia Kraus, an associate professor of medicine at Duke University and lead author of a study that challenges the conventional wisdom on diet and osteoarthritis.

Millions of older Americans suffer from the pain and stiffness of osteoarthritis -- a deterioration of bones and cartilage in the joints. Unlike rheumatoid arthritis, which experts know is caused by inflammation brought on by immune system dysfunction, the causes of osteoarthritis remain unclear.