1 Calcium and vitamin D intake. 2  A diet low in calcium and vitamin D makes you more prone to bone loss. 3  Medication use. 4  Some medicines increase the risk of osteoporosis. 5  Activity level. 6  Lack of exercise or long-term bed rest can cause weak bones. 7  Smoking.
Signs and Symptoms. 1  Nail splitting affects the fingernails and the toenails. The condition may appear as a single horizontal split between layers of the nail plate at the growing end or as multiple splits and loosening of the growing edge of the nail plate.
I had bitten my nails for over thirty years so my nails are flatter which I think is the cause of the splitting. The nail on my middle finger grows in a bit and then splits as the nail eats longer. I have tried crazy glue and cutting it short but it just keeps happening.