1 A diet low in calcium and vitamin D makes you more prone to bone loss. 2  Medication use. 3  Some medicines increase the risk of osteoporosis. 4  Activity level. 5  Lack of exercise or long-term bed rest can cause weak bones. 6  Smoking. 7  Cigarettes are bad for bones, and the heart, and lungs, too. 8  Drinking alcohol.
When Toes Turn Dark. Nails change colors for multiple reasons. The most common culprit for a black toenail is blood under the hard tissue. Damage to the end of the toe causes blood to leak through the nail bed and stain the keratin a dark color. This is also known as a subungual hematoma, or a bruise under the nail.
1 Compulsive washing of the hands or feet can also contribute to brittle nails. 2  Age: As we get older, our bodies become less able to retain moisture, which eventually causes our hair and nails to become brittle and easily damaged.