Key Points
Although there are numerous mechanisms by which micronutrients can be expected to influence the development of osteoarthritis (OA), there has been insufficient research to draw definitive conclusions.
The strongest evidence points to a possible protective effect of vitamin D in the development of hip OA and the progression of knee OA.
One observational study suggested a protective effect of vitamin C for progression of knee OA. Because intake of vitamin E and β-carotene bore no relationship to OA incidence or progression in that study, the mechanism of benefit of vitamin C may be mediated through nonantioxidant properties.
Clinical trials of vitamins E, C, and A and selenium have produced negative or inconsistent results.
There have been numerous positive clinical trials of glucosamine and chondroitin products for OA. Issues of biological plausibility, publication bias, and methodological problems cloud interpretation of these trials.