Hi Javy,

Here is a page addressing exactly this issue:
Low Carbezine

In this article, the author names some specific nutrients that, when absent, can cause hair loss. There is also general good stuff about vitamins.

By the way, I find Dana Carpender's Low Carbezine to be an invaluable resource for all things low carb. It's in my big three: this site, Dana's and Low Carb Luxury.

Dana has also written an excellent book entitled "How I Gave Up My Low Fat Diet and Lost 40 Pounds".

She has a LC cookbook out that I haven't read, but will get as it is supposed to be excellent.