"The symptoms usually start somewhat gradually with mild pain that may be intermittent, but over the years can intensify, become persistent and ultimately lead people to seek medical attention," said Dr. Timothy McAlindon, Tufts Medical Center.
Currently there are no medical treatments that can prevent the pain of osteoarthritis, so researchers looked to vitamin D to see if it might help.
Dr. McAlindon and his co-authors conducted a randomized controlled trial that involved 146 patients over age 45 who had moderate levels of knee pain. Half were given 2,000 units of vitamin D every day. Others received a placebo.
The result? Researchers say taking daily vitamin D didn't seem to make much of a difference to people with osteoarthritis in their knee.
"Vitamin D supplementation at a level sufficient to raise their blood levels to those considered healthy did not make any difference over the two-year period to how much pain they experienced or the amount of structural damage that occurred to cartilage or to the surrounding bone," said Dr. McAlindon.
The study appears in the Journal of the American Medical Association (JAMA).