I ask every patient to take Vitamin C after surgery. It's not just because I'm trying to keep them from catching the flu. I'm trying to prevent a really annoying problem called complex regional pain syndrome (CRPS for short). CRPS is a pain syndrome whose cause is not well understood. It can cause a sense of burning pain in a limb and even result in physical changes like redness, swelling, and loss of normal sweating functions. It usually happens after some sort of injury and once it sets in, it can be difficult to treat.
The science behind Vitamin C and CRPS hasn't been totally validated. However, the evidence is strong enough that the AAOS, my professional society, has recommended Vitamin C in its practice guidelines for distal radius fractures. In my practice, I encourage patients to take 500 mg of Vitamin C for 2 months after an injury or a surgery. In fact, there is no harm in continuing this as a daily habit. It might even keep you from catching a cold this winter!