I had read on the forum that another B vitamin, Biotin, is also helpful with the hair loss. I am only 6 weeks post op, and haven't had any hair loss yet, but I have already started taking a Biotin supplement that I got at Walmart.
"Biotin is often recommended for strengthening hair and nails.... Biotin supplements are often recommended as a natural product to counteract the problem of hair loss in both children and adults."
http://en.wikipedia.org/wiki/Biotin
I don't know yet if it will help me with the hair loss (which is what I am hoping!) but since I started taking it, my nails are really strong. I have always had thin brittle nails that never got very long. I now have nails long enough to actually paint
(past the end of my fingertips) and I planted a tree in my front yard yesterday and didn't break a single one. I also take a B-complex supplement in addition to my multivitamins and I make sure I'm getting at least 60 grams of protein per day, so I think all of that contributes to the nails getting stronger. Hopefully it will also help with the hair loss later!