Ah, finally getting that superfluous nipple removed. Good to hear it! Not only did it not produce milk but it would always get hard when the temperature dropped and irritate your hand when you made armpit farts.
I don’t know of any special supplements. I’ve heard that taking vitamin C and E can help but I’m too busy to actually open up medline and do any research at the moment. If you like, go to pubmed.com and it’ll redirect you to a site to look for research. I’m sure taking multivitamins won’t hurt but I’d probably avoid any unproven application of some other product directly to the wound. Most doctors will give you some polysporin or other ointment to put on it to keep it relatively clean and moist for proper healing. If the wound is closed by primary intention it should heal fine in a few weeks.
Good luck with it. Hopefully you’ll have a cute member of the opposite sex take care of you in your recovery period.
ps. What does a pig put on his surgical wound?