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.
Posted by in Fingernails. ANSWER: Fingernails can curl from a B12 or iron deficiency. More Info: One of the medical terms for curled fingernail is âkoilonychiaâ, more commonly known as âspoon nails.â The main cause of this is iron deficiency anemia, or a lack of enough B12. This vitamin is found generally in meat products, not fruits and vegetables.