Interesting. I've had a somewhat similar experience. My fingernails used to be somewhat ugly, with bloody hangnails, many leukonychia (white spots), pronounced vertical ridges, and irregularly opaque distal edges. Now they are somewhat attractive, with very few and shrinking hangnails, only one tiny white spot, gradually disappearing ridges, and uniformly bright white distal edges. The shiny white edges are what really stand out at this point.
A couple people in person and a bunch of online sources claimed that leukonychia are from hitting one's fingernails on headboards or other hard objects in one's sleep. This was utterly ridiculous in my case, because I have never owned a headboard and the one bed of my childhood that did have a headboard had such a small one that it was too difficult to reach without awkward stretching. At the time I was told that leukonychia is caused by headboards my bed had no headboard and was not within arms reach of anything hard like a wall or anything else and I've never been known to sleepwalk. I even tried banging my fingernails on a headboard as hard as I could handle (and I wasn't a very heavy sleeper--so the pain would likely have woken me up if I did it in my sleep) to see if it created any white spots. None appeared. Besides, my spots were little, fairly uniform, round white things, not thick white lines or big splotches one might expect from hitting the fat edge or flat face of a headboard. Maybe leukonychia is caused by banging for others, but certainly not for me. Yet it gets repeated by some people as though it were dogma that's true for everyone--and I've never seen a scientific reference given to support this.
Within a few weeks of adopting a Paleo diet the white spots and ridges started diminishing and have never been as bad as they once were (though increasing fruit, winter squash, nightshades and other plant carbs in my diet worsened things somewhat again for a while, but not as bad as it had been--though this was interesting confirmation that diet was the cause for me)--yet I made no changes in my bed or bedroom at the time of my first dramatic reduction in these symptoms. The only significant change was dietary. Going carnivore helped further, and brought out the white of the edges. I also accidentally found that zinc supplementation helped to further diminish the white spots. I learned online that zinc deficiency is linked to leukonychia, though some deny it. In my case the connection appeared to be confirmed. The headboard folk tale also didn't explain why my ridges were diminishing, hangnails disappearing, etc.