First of all, like anything, your hair needs nutrients to grow. Protein is key to a balanced diet, so hit the butcher and breakout the grill, or get fancy with oysters and sashimi–whatever it takes to get your amino acids. Nuts, eggs, yogurt, and other dairy products are great in the protein department as well. You need to continue to eat lots of whole grains, fruits and veggies, which also contain vital nutrients. If eating your vitamins is less your thing, maybe pickup some supplements such as: folic acid, fish oil, flaxseed oil, and biotin.