Just something I've noticed over the past few years.... Nails can provide an interesting indication of your nutrition. Keep in mind that the toenail usually take about 6 months to grow one entire length. Looking at my toenails, I notice a distinct difference in between the bottom half and the top half. The top half is much more brittle, soft, and opaque. The bottom half is much stronger, clearer, thicker, and more shiny. I can relate this to my diet changes over the past six months. The unhealthy part of the nail grew when I had hardly any knowledge of healthy dieting and used to severely limit food intake to try to make weight for wrestling. My eating habits were terrible. Then, I can feel with my finger, there is a ridge (on every toenail) that actually makes the transition to the healthy part of the nail. This part of the nail grew after I started reading these boards and doing some research on my own about optimal and effective dieting for an active athlete. Looking at my fingernails, I can also see a difference. However, since fingernails grow much faster, the patterns seen reflect the short-term. For example, right now I can see thin white shallow curves that go from side to side on EACH nail in the same place, lengthwise. I can actually go through each one and recall the times in the past month or so that I've had to cut weight for tournaments. Each line is maybe a 0.5 mm span of nail that grew while I was cutting weight. These lines are opaque, soft and brittle. I just found these things very interesting, and I stared at and examined my nails for like five minutes straight when I first discovered it, slowly going through my past eating habits. I probably tend to take interest in small things like this more than most people, I know I really found this fascinating for some reason when, on my own, I discovered the relation to the differences in nail texture at various points on the nail to my past eating habits Has anyone else ever noticed this? I was kinda curious as to what nutrients specifically cause these changes.