About 99% of the body’s calcium is stored in the skeleton. The remaining 1% is present in the blood and other body fluids, where it is critical to the maintenance of a wide range of body functions.
To ensure there is sufficient calcium available to maintain vital body functions, calcium moves out of the bones and into the blood as required.
Osteoporosis occurs when the bones lose calcium more quickly than it can be replaced, and over time this leads to a decline in the density and mass of the bones, makes them more susceptible to fracture.
Most of our bone mass is laid down during childhood before puberty, and we reach our peak bone mass at about 30 years of age. After that point, the bones become thinner and weaker. In women, this process accelerates after menopause, due to declining oestrogen levels.
To prevent osteoporosis, it is essential that you get adequate calcium and vitamin D over the course of your life, including in childhood.
Some health conditions increase your risk of developing osteoporosis. These include diseases affecting the thyroid and parathyroid glands, rheumatoid arthritis, coeliac disease (and other chronic bowel conditions), chronic liver and kidney disease, and eating disorders . Some medicines also increase the risk of osteoporosis; corticosteroids (commonly used to treat asthma and rheumatoid arthritis) are one example, but there are also many others. Talk to your doctor about the specific medicines you take.
Other risk factors for osteoporosis include:
- Being female
- Getting older
- Being Caucasian, Asian or Latino
- Having a slight or slender frame; being underweight
- Having a family history of osteoporosis or fractures
- Having a personal history of broken bones during adulthood
- Experiencing an early menopause
- Being inactive for an extended period at some stage of life
- Excessive alcohol consumption
- Smoking (which is associated with increased risk of fracture and delayed healing )
- For women, experiencing times of infrequent or absent periods at some stage in life (other than due to pregnancy, menopause or hysterectomy)
- For men, having low testosterone levels (which may be suggested by low libido and erectile dysfunction)