DEAR READER:
Lack of essential fatty acids such as an omega 3 deficiency, can cause brittle nails that split. Other than this unlikelihood, it appears to me that you probably have a form of nail disease or a nail disorder in one of the more than 20 possible forms.

Onychorrhexis is one such form causing brittle nails that peel, have vertical ridges and often split in a vertical manner. While the condition can be hereditary, a common cause is the use of strong cleaning solutions in the home or workplace. Oil or paraffin treatments can be used to soften and re-hydrate nail plates, but a physician should be consulted to confirm my suspected diagnosis. If necessary, he or she can refer you to an appropriate specialist in your area.