Should I be worried about my fingernails?(change of eating habits?)

Factual Questions
#1

I’ve noticed over the past couple of weeks that all my fingernails are discolored under the nails, right at the tips. Right before the nail grows out there are 1-2mm horizontal bands that follow across the curve of the nails. They’re a couple of shades darker than the normal pink under my nails, and don’t hurt. I’m apparently not phasing a search right, since I’ve yet to find anything through a search engine that describes it. Does anyone know if it’s a symptom of anything? I’m looking more for “clues” than medical advice…

I’m also curious if it could be connected to the fact that I changed my eating habits, for the better, several weeks ago. I have a wicked sweet-tooth, and I decided that if I don’t want to become really unhealthy, I should cut back on my sweets intake- by about 90%. It makes me wonder if there actually are some nutrients in sweets (chocolate, candy, pastries etc) that I’m currently lacking, since some things I have been able to find about fingernails say that vitamin deficiencies can show up in your nails. Do sweets provide more than calories?

#2

Hmm… well I would honestly just call your doctor if I were you. However, I do know that fingernails grow slowly (I believe it’s about a tenth of a millimeter per day) enough that if the banding is at the tips of your nails (fingernails are generated at the cuticles, not at the fingertips), it’s most likely not due to your recent change in diet unless “several weeks” is more like several months.

#3

True, nails do take a long time to grow but it’s really the skin under the nails, not the nails themselves, that are showing this strange change.