I don't take vitamins for hair anymore because the results were just way too inconsistent. I decided to focus on my diet and I take a few supplements. I started about a month ago and my eyelashes are longer. Not sure the results for my head, though.
Vitamin K2 oil
Biosil -- this is hair related, but I am taking it for healthy bones. The reviews say it makes the hair thicker, but not necessarily make it grow faster.
Good Belly probiotics
I'm increasing my intake of vegetables and fruits. I was doing okay, but I think I'm going to aim for having a morning smoothie and having 3 - 4 cups of veggies for lunch. We'll see lol
Also up'd my water. I caved in and just started buying big ole packs of water bottles.