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.
Splitting Fingernails. Fingernails can crack and break because of several reasons. The most common factor being, nail-hardening products and nail polish that may be drying up the nails. However, sometimes health imbalances can also make the nails brittle and cause them to split. Fingernails are made up of a structural protein called keratin.