Osteoporosis (porous bones) is a condition, which is most often found in post-menopausal women, particularly those with smaller bones. Due to lack of oestrogen that occurs because of menopause, a lack of calcium in the diet, or a lack of weight bearing activity, the bones begin to lose their structure. In some people this shows as an extreme curvature of the upper back, due to the loss of bone in the vertebrae in the neck and thoracic areas, which forces the head downwards. More commonly it is seen in the thinning of the upper part of thighbone. Most of the broken hip experienced by older people is caused by this bone loss. Bones are active tissues, giving off and replacing calcium continually. At about age 35 women's bones begin to become less dense. This happens a little later for men. After menopause, female bone loss is increased because of lack of oestrogen. By age 65, the average woman has lost 26 percent of her bone density, while the average man has lost 9 percent.

Common causes of osteoporosis (in both men and women) include:
- Genetics/family history
- Lack of weight-bearing exercises
- Smoking
- Inadequate calcium intake throughout life

The best methods of reducing the risk are:

• A lifelong intake of calcium and or calcium supplements should be included in your diet. Non-fat milk, cheese, broccoli, kale, and beans and calcium supplements are good sources. Post-menopausal women should take 1500-mg calcium daily.
  
• Do not smoke, and do not drink too much.
  
• Do weight-bearing exercises like dancing, gardening, housework, walking, running and so on.
  
• For post-menopausal women, hormone replacement therapy is often a possibility.

Eat Your Way to Strong Bones

The main mineral in bones is calcium, one of whose functions is to add strength and stiffness to bones, which they need to support the body. To lengthen long bones during growth, the body builds a scaffold of protein and fills this in with calcium-rich mineral. From the time you're 11 until you're 24, you need about 1,200 milligrams (mg) of calcium each day. Bone also needs vitamin D, to move calcium from the intestine to the bloodstream and into bone. The recommended daily allowance of Vitamin D is 400-800 IUs. You can get vitamin D from short, normal day-to-day exposure of your arms and legs to sun, cod liver oil, liver and from other foods fortified with the vitamin. Also needed are vitamin A, vitamin C, magnesium and zinc, as well as protein for the growing bone scaffold.