Reflex sympathetic dystrophy (RSD) is a set of symptoms that can develop in the legs, arms, feet, and hands after fractures and other injuries. Also called complex regional pain syndrome (CRPS), its symptoms include changes in skin temperature and color over the affected area, accompanied by burning pain, sensitivity to touch, sweating, and limitation of range of motion. The cause of RSD is unknown, and it is very difficult to treat.
Two studies performed by a single research group suggest that RSD might be preventable by timely use of vitamin C following a fracture. The most recent of these compared placebo against three different dosages of vitamin C in 416 people with wrist fractures.
For a period of 50 days, participants received either placebo or vitamin C at a dose of 200 mg, 500 mg, or 1500 mg daily. They were then followed to see how many developed RSD. The results indicated that approximately 10% of those given placebo developed RSD, while less than 2% of those given vitamin C in the 500 mg or the 1500 mg daily dose did so. (To add a technical note: this difference wasstatistically significant .) The 200 mg dose of vitamin C did appear to offer some protection as well, but not as much.
Based on these findings, the researchers concluded that people who have suffered an injury placing them at risk for RSD should take vitamin C at a dose of 500 mg daily. However, it should be noted that confirmation by an independent research group is still lacking.