Very concise summary of what helps, and what doesn't in these 2 docs:
Get enough protein/carbs while healing. Pretty self-evident. Then
Arginine in doses of least 30 g (I've found elsewhere 1g/kg) helps a LOT - but this is mostly intravenous, and more than ~6g per dose is not tolerated by the digestive system, and also needs to be diluted at 115 ml / g (so 6 g in ~ 700 ml water) Needs to be taken on an empty stomach to be fully effective
Glutamine helps, not directly, but as a general supportive measure as your body needs more of it during injury (found elsewhere that maximum tolerated well is 0.65g / kg bw, best dosage they tested was 0.75 but stopped increasing as it wasn't tolerated)
HMB (betaHydroxybetaMethylButryate) also helps, but mostly to preserve muscle rather than to aid healing
Ornithine (amino acid) helps, and could probably be used to reduce arginine dosage (it's a metabolite of arginine, and is one of the 3 ways arginine helps healing, Other two are NO (direct) and IGF(stimulates release))
Ornithine Ketoglutarate - good for supplying ornithine, but apparently has some other beneficial effects. No studies to support this that I've found, but many of the studies supporting ornithine used OKG
Vit C - up dose to multi-gram (no news here)
Vit A, Iron, Zinc etc - only problem if deficient
Omega 3 - this document lists it as hindering, but later research shows that what this document saw as reduction in healing actually helps reduce scarring