Osteoporosis makes your bone weak and more likely to  break. It is said to be common among elderly people. 

> WHY? As people goes through aging (especially women), Estrogen production ceases/lowers down. As the hormone goes down a bone-forming cell decreases as well called osteoblast. As this two is directly proportional with each other, so BOTH lowers down. After which, a bone destroying cell goes up. 

> When bone - forming cell is less than bone - destroying cell, then  a person is high-risk for OSTEOPOROSIS.

Thus, increasing Vitamin D and calcium in the diet would help. And decreasing intake of coffee and cola, for this will increase the calcium loss from the body.