Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density (BMD) is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered. Osteoporosis is defined by the World Health Organization (WHO) as a bone mineral density that is 2.5 standard deviations or more below the mean peak bone mass (average of young, healthy adults) as measured by DXA

Osteoporosis risks can be reduced with lifestyle changes and sometimes medication Medication includes calcium, vitamin D, bisphosphonates and several others.

Risk Factors for osteoporotic fracture :-
Vitamin D deficiency—low circulating Vitamin D is common among the elderly worldwide. Mild vitamin D insufficiency is associated with increased Parathyroid Hormone (PTH) production. PTH increases bone resorption, leading to bone loss. A positive association exists between serum 1,25-dihydroxycholecalciferol levels and bone mineral density, while PTH is negatively associated with bone mineral density.
Excess alcohol —small amounts of alcohol are probably beneficial. Bone density increases with increasing alcohol intake. However chronic heavy drinking (alcohol intake greater than 3 units/day) probably increases fracture risk despite any beneficial effects on bone density
Malnutrition —nutrition has an important and complex role in maintenance of good bone. Identified risk factors include low dietary calcium and/or phosphorus, magnesium, zinc, boron, iron, fluoride, copper, vitamins A, K, E and C (and D where skin exposure to sunlight provides an inadequate supply)
Soft drinks —some studies indicate that soft drinks (many of which contain phosphoric acid) may increase risk of osteoporosis;[29] Others suggest soft drinks may displace calcium-containing drinks from the diet rather than directly causing osteoporosis
Tobacco smoking —Many studies have associated smoking with decreased bone health, but the mechanisms are unclear. It has been proposed tobacco smoking inhibits the activity of osteoblasts, and is an independent risk factor for osteoporosis. Another is that smoking results in increased breakdown of exogenous estrogen, lower body weight and earlier menopause, all of which contribute to lower bone mineral density.