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.
Tertiary hypothyroidism - Brittle finger nails Xeroderma. Brittle fingernails: Tools. Symptom Checker Â» Drug side effect causes of Brittle fingernails . The following drugs, medications, substances or toxins may possibly cause Brittle fingernails as a side effect. Oxypentifylline Trental Cyclosporine; Sandimmune; Consupren [See detailed list of 8 drug side effect causes of Brittle fingernails]