This consists of low-dose estrogen and progesterone treatments that can unquestionably slow bone loss and prevent fractures. Being chronically underweight or having a slight frame. A poor diet, low in vitamins and minerals, especially calcium. Being sedentary and lack of weight-bearing exercise. In women this lowers the estrogen content of the blood, thus weakening the bones.
Smoking is particularly dangerous for women who have other risk factors for osteoporosis.
It's not known why heavy drinking weakens the bones - perhaps because heavy drinkers often eat a poor diet. Long term use of certain medications. So can long-term use of thyroid hormones. It's better to get the calcium you need from food than from pills because food also contains other nutrients you need - including those, such as vitamin D, magnesium, and boron, that are important in building bone. Until recently, there have been serious questions about whether calcium supplements do any good.