For a number of years I had brittle nails. I was frustrated because I was not able to maintain decent looking nails for longer than a week. So regularly I went to have my manicure done and had clear polish put on my nails. This went on for years. I tried different nail polish, but nothing changed much. I even talked to my doctor and he suggested taking vitamin D but really no perceptible change with all my efforts.
So one day my manicurist suggested to skip the nail polish to see what would happen.
It took a few weeks, but the change was unbelievable. My nails grew without breaking or pealing. I could actually grow nails and keep them without breaking. They are strong and just normal looking. It must have been the nail polish remover that weakened and dried the nails. Now I do not use nail polish at all, even tho I like it, but I will save it only for special occasions.