Vitamin/Supplements for Puppy hair growth

[Discussing Labradoodles & Goldendoodles]

My goldendoodle puppy recently had surgery to repair a broken leg. She is doing absolutely great, and we are so happy with how well her recovery has gone thus far! She really is an absolute trooper!! For the surgery they had to shave the affected leg and cast it. Yesterday her cast was removed and we were able to finally see her leg since the surgery. She has a very thin layer of hair present so it isn't completely "bald" but we are anxious to have her hair grow back to a more normal length. My concern is not appearance related but her coat is what helps her regulate her body temperature and we are nearing very cold weather conditions. I fear the lack of hair on this leg will cause her problems in the winter. The spot of her front leg that had to be shaved for her IV has been a little slow to grow back, although it is much thicker than her back leg (most likely due to the fact that it was not casted). 

Does anyone know if there are any vitamins or supplements that promote hair growth that would be safe for a puppy? Or has anyone else experienced this and have suggestions for ways to make sure her leg stays warm when she has to go outside in cold temperatures? She is still recovering and her outdoor time is limited to going to the bathroom, but she will eventually need to exercise the leg outside to regain muscle strength and full range of motion.

Any suggestions or similar experiences that you could share with me would be greatly appreciated! I already overload my vet with a million questions a week so I figured I would reach out here before contacting them.

We are so proud of our sweet puppy for how well she has handled everything and grateful for the amazing progress she continues to make everyday! I just want to ensure she keeps getting better and has no further set backs! 

[Karen, Jasper and Jackdoodle]

Vitamins won't do a thing to promote hair growth or make the hair grow back quicker. 
There are all kinds of "snowsuit" type garments you can buy for dogs, that cover their legs. You might also try just cutting the feet off a pair of toddler girl's stretchy knee socks to make some doggy "leg warmers".

[Karen, Jasper and Jackdoodle]

Oh, and I hope her recovery goes quickly and well! 

[DonMarie and Picco]

I hope her healing goes well.  I sure wouldn't know how to keep a pup calm during healing but they do heal fast!   The socks are a good idea.  You can have fun with colors & prints.