'Dem bones, dem bones!'

Our bones operate pretty much like our bank accounts, except that calcium and bone are constantly being deposited and withdrawn. That is, our body constantly removes old bone and grows new bone. Vitamin D and hormones such as oestrogen and testosterone are essential in this process. If we deposit more minerals (such as calcium and phosphorous) than we remove, bones may remain fairly strong and healthy. This usually happens up to about age 30.

Eventually more minerals are withdrawn than deposited and if this continues unabated our bones become bankrupt of calcium, losing their hard, dense structure. This makes them porous, brittle and easily breakable. This is osteoporosis, which essentially means 'porous bones'.

The making of osteoporosis

Osteoporosis becomes evident as we get old. Women are a lot more at risk than men, since at menopause we produce no oestrogen. But as men age, testosterone levels decrease too.

Others who are at risk of osteoporosis include people with thyroid trouble, diabetes, family history of osteoporosis, women who have never had children, and lifestyle risk factors like heavy smoking and alcohol drinking, low-calcium diet and lack of exercise. Some medications, such as phenytoin, phenobarbital and oral steroids like prednisone, when taken long term can put us at risk too.

Drug treatment

Whatever the doctor prescribes, calcium and vitamin D are almost certain to be a part of treatment. Our skeleton contains nearly 99 per cent of all the calcium in our bodies. We may get calcium in the diet, but often it's not enough. Most adults need at least 1,000mg of calcium each day. Vitamin D increases the absorption of calcium into the body.

We may 'consume' vitamin D from sunlight exposure.

For the menopausal woman, prescribing oestrogen (hormone replacement therapy) used to be the mainstay of treatment for osteoporosis. But when we weigh up the adverse effects of long-term hormone replacement (especially when given by mouth), with its benefits in managing osteoporosis, there are many complex, unanswered questions.

Due to the availability of a fairly new class of synthetic drugs called bisphosphonates, many women and their doctors have been able to bypass hormone replacement therapy in managing osteoporosis. Some still use hormone replacement therapy plus a bisphosphonate.

Bisphosphonates, used by men and women, slow down the loss of bone tissue and increase bone density in the spine and hip, reducing the risk of fractures. The group includes alendronate (Fosamax), ibandronate (Boniva), pamidronate (Aredia), risedronate (Actonel) and etidronate (Didronal). Hormones such as calcitonin and parathyroid hormone are other drug options administered by injection.

Yes we can stop it!

There's a pill for every illness, but let's look at how we can prevent this 'ill' from happening — the sooner the better. First off, modifying the aforementioned lifestyle risk factors is advisable.

Long before the potential kick-off of the process (around age 30), we must start beefing up daily calcium and vitamin-D intake (preferably through the diet), and regularly practise weight-bearing and muscle-strengthening exercises. If we already have osteoporosis, we can slow or halt further bone loss.

Dahlia McDaniel is a pharmacist and final-year doctoral candidate in public health at the University of London; email: yourhealth@gleanerjm.com.