I've noticed that ends of some of my fingernails look flat and even a bit concave. I tried to research it on the internet and, from what I found, I think I might be lacking zinc, protein and iron in my diet. Has anyone else ever experience something like this? I'm just a bit worried, because it seems like it's getting a bit worse. I have a doctor's apt next month, but I'd like to try and fix it before then. Can anyone recommend good sources of zinc, protein and iron? Thanks.