Iron, B vitamins and kelp will all help promote hair growth. Also, massaging your scalp daily for a few mins encourages the blood to flow to your hair follicles. When I was growing my hair long a few years ago, also used to put Guiness on my hair each night following the advice of a friend. Can't say for sure it helped speed up growth, but it made my hair gorgeous and glossy. It was pretty smelly though, but I was single at the time so going to bed with hair all matted with beer and smelling was ok!