You're 19, you're most likely done with puberty and growing, but some people can bloom late, and keep going into their early 20's. Height = genetics, I don't know of any specific food or legit supplement to improve it. Also, lifting weights will not stunt ur growth, crush your growth plates, etc etc etc. There was actually a thread on this a little earlier if u can find it, ill try and post a link later. It basically said the stunting of growth is a myth, but what will stunt your growth are steroids, so don't use those until you're fully developed. Your doctor could probably tell you if you're done with puberty or not.