Post lap band surgery significant hair loss

My surgery date is June 2009. I have had significant hair loss over the last year or more. My hair is getting thinner and thinner. I've been using a protein conditioner for about 8 mo.s now. I started prenatal vitamins about 1 mo. ago. I've been taking biotin for a week now. Does anyone have any suggestions that they have had actual noticeable success in stopping major hair loss?