Osteoporosis
Also known as: bone density loss, low bone mass
Medically reviewed by Hormone Journal Editorial Team · Last reviewed 2026-05-22
Osteoporosis is a skeletal disease affecting roughly 2 million Canadians, in which progressive bone density loss raises fracture risk from minimal trauma.
What it is
Osteoporosis is a skeletal disease affecting approximately 2 million Canadians — with a further 4.5 million living with osteopenia (low bone density) — in which reduced bone mineral density and deteriorating bone microarchitecture raise the risk of fractures from minimal trauma. Hip fractures are the most serious consequence, carrying a 20–30% mortality rate within one year in older adults. Also called bone density loss or low bone mass, osteoporosis is often described as a silent disease because bone loss produces no symptoms until a fracture occurs. Globally, the condition is responsible for roughly 9 million fractures annually.
Osteoporosis is strongly hormone-driven. Estrogen deficiency at menopause is the single most important risk factor in women; testosterone deficiency plays an analogous role in men. While some bone loss is a normal part of aging, osteoporosis represents loss that has crossed the threshold at which everyday activities — a minor fall, bending, or even coughing — can cause a break.
In Canada, Osteoporosis Canada and the 2010 CMAJ clinical practice guidelines provide the primary framework for screening, diagnosis, and treatment decisions.
Causes and mechanism
Bone is living tissue in a constant cycle of breakdown (resorption by osteoclasts) and rebuilding (formation by osteoblasts). Osteoporosis develops when resorption chronically outpaces formation.
Hormonal drivers are the most clinically significant:
- Estrogen deficiency — estrogen directly suppresses osteoclast activity. After menopause, women can lose 2–4% of bone density per year in the first 5–10 years, a rate far exceeding normal age-related loss.
- Testosterone deficiency in men — testosterone supports bone density both directly and through its aromatization to estrogen.
- Premature ovarian insufficiency (POI) and surgical menopause — earlier and more prolonged estrogen deficiency produces greater cumulative bone loss.
- Glucocorticoid excess — long-term corticosteroid use is the most common drug-related cause; cortisol directly inhibits osteoblast function.
- Hyperthyroidism and hyperparathyroidism — both accelerate bone turnover in ways that favour net resorption.
- Growth hormone deficiency — GH and IGF-1 are required for normal bone formation.
Non-hormonal risk factors include advancing age, family history of osteoporosis or hip fracture, low calcium and vitamin D intake, physical inactivity, smoking, excess alcohol, and low body weight or a history of anorexia nervosa.
Symptoms and diagnosis
Osteoporosis itself causes no symptoms. The first sign is often a fragility fracture — a break from an impact that would not normally injure a healthy bone.
| Fracture site | Clinical features |
|---|---|
| Spine (vertebral) | Height loss, kyphosis, chronic back pain; many occur without a specific injury |
| Hip | Highest mortality and disability; often requires surgery |
| Wrist (distal radius) | Frequently the first fragility fracture; typically from a fall on an outstretched hand |
| Shoulder (proximal humerus) | Less common; associated with significant functional impairment |
Diagnostic tools:
- DEXA scan — the gold standard. Measures bone mineral density (BMD) at the hip and lumbar spine. Results are expressed as a T-score: above −1.0 is normal; −1.0 to −2.5 is osteopenia; below −2.5 is osteoporosis.
- FRAX tool — calculates 10-year fracture probability using BMD plus clinical risk factors. Used in Canada to guide treatment thresholds.
- Blood tests — calcium, phosphate, vitamin D, PTH, bone turnover markers, thyroid function, and sex hormones help identify secondary causes.
- Spine X-ray — identifies existing vertebral fractures that may have gone unnoticed.
In Canada, DEXA scanning is available through LifeLabs and Dynacare imaging networks, and is covered under provincial health plans for eligible patients (criteria vary by province).
Treatment options
Treatment combines lifestyle measures, nutritional support, hormonal correction where applicable, and pharmacological therapy for those at elevated fracture risk.
Lifestyle and nutrition:
- Calcium: 1,000–1,200 mg per day through diet and supplementation combined.
- Vitamin D: 800–2,000 IU per day to support calcium absorption and bone metabolism.
- Weight-bearing and resistance exercise (walking, running, strength training) stimulate bone formation.
- Fall prevention — balance training, medication review, and home hazard assessment reduce fracture incidence independently of bone density.
Hormonal treatment:
- Hormone replacement therapy (HRT) in women: estrogen is highly effective at preventing bone loss and reducing fracture risk; it is considered first-line for perimenopausal and early postmenopausal women with osteoporosis or significant bone loss.
- Testosterone replacement in hypogonadal men improves bone density.
Pharmacological therapy:
| Agent | Mechanism | Fracture risk reduction |
|---|---|---|
| Bisphosphonates (alendronate, risedronate, zoledronate) | Inhibit osteoclast activity | 30–70% depending on site and agent |
| Denosumab (Prolia) | Monoclonal antibody blocking osteoclast activation | Comparable to bisphosphonates; 6-monthly injection |
| Romosozumab (Evenity) | Stimulates bone formation and reduces resorption | Used for high-risk patients |
| Teriparatide / abaloparatide | Anabolic; stimulates new bone formation | Reserved for severe or treatment-refractory cases |
| Raloxifene (SERM) | Selective estrogen receptor modulator | Modest fracture reduction; also reduces breast cancer risk |
Denosumab must not be stopped abruptly without transitioning to another agent, as rebound bone loss can occur rapidly.
When to see a clinician in Canada
Seek a bone density assessment if you:
- Are a woman aged 65 or older (routine DEXA is recommended by Osteoporosis Canada)
- Are a postmenopausal woman under 65 with risk factors such as family history, low body weight, prior fracture, or smoking
- Experienced premature menopause or prolonged amenorrhea
- Have taken corticosteroid medications for more than three months
- Have sustained a fracture from low-impact trauma
- Are a man over 70, or younger with hypogonadism or long-term corticosteroid use
Most Canadians with osteoporosis are unaware of it until they fracture. Early detection through DEXA scanning — before the first fracture — is when preventive treatment has the greatest impact. Canadian telehealth platforms such as Felix, Maple, Cleo, and Phoenix can facilitate initial assessment and referral, though DEXA interpretation and prescribing of bone-active medications typically requires an in-person clinician.
Limitations and open questions
Research is still emerging on several aspects of osteoporosis management. The optimal duration of bisphosphonate therapy — and when a "drug holiday" is appropriate — remains an area of active investigation, with guidance varying across guidelines. The long-term cardiovascular safety of calcium supplementation (as distinct from dietary calcium) is not fully resolved; some meta-analyses suggest a modest increased risk, while others do not. Health Canada has not yet issued updated guidance on romosozumab's cardiovascular risk signal identified in one pivotal trial, and clinicians currently weigh this on a case-by-case basis. The role of bone turnover markers in routine monitoring is debated, and their availability through provincial laboratory coverage varies. Evidence on optimal screening intervals for men and on osteoporosis management in transgender individuals on hormone therapy is limited and evolving.
FAQs
Is osteoporosis only a women's disease?
No, though it is considerably more common in women. Men account for approximately 20–30% of all osteoporotic fractures. Because testosterone declines more gradually than estrogen, men's bone loss tends to become clinically significant after age 70, roughly a decade later than in women. Male osteoporosis is frequently underdiagnosed because screening is applied less consistently to men; common causes include hypogonadism, long-term corticosteroid use, excess alcohol, and age-related bone loss.
Can osteoporosis be reversed?
Treatment cannot fully restore bone that has already been lost, but it can meaningfully slow further loss and reduce fracture risk. Anabolic agents such as romosozumab and teriparatide can actually increase bone density over time — romosozumab has been shown to increase lumbar spine BMD by roughly 13% over 12 months in clinical trials. More importantly, treatment substantially cuts fracture risk even without fully normalizing bone density, and preventing the first fragility fracture is the primary goal, since subsequent fractures become progressively more likely after the first.
How does menopause affect bone density?
Estrogen directly suppresses osteoclasts, the cells responsible for breaking down bone tissue. When estrogen declines at menopause, osteoclast activity is no longer effectively restrained, and bone resorption significantly outpaces formation. Women can lose 2–4% of bone density per year in the first 5–10 years after menopause — a rate far exceeding normal age-related loss. This accelerated phase is the primary reason osteoporosis is so much more prevalent in older women, and why HRT started early in the menopausal transition is highly effective at preventing it.
Does calcium supplementation alone prevent osteoporosis?
Calcium is necessary but not sufficient on its own. Adequate calcium (1,000–1,200 mg per day) and vitamin D (800–2,000 IU per day) are essential foundations, but they do not fully prevent or treat osteoporosis in people at elevated risk. Weight-bearing exercise, correction of hormonal deficiencies, and pharmacological therapy where indicated are all needed for meaningful fracture risk reduction. Dietary calcium is preferred over supplements where possible, as some meta-analyses have raised questions about modest cardiovascular risks associated with high-dose calcium supplementation.
Is DEXA scanning covered in Canada, and how do I access it?
DEXA scanning is covered under provincial health insurance plans for eligible patients, though criteria differ by province — most cover women aged 65 and older and individuals with specific risk factors such as prior fragility fracture or long-term corticosteroid use. In many provinces, a physician or nurse practitioner referral is required. Scans are performed at hospital radiology departments and through private imaging networks such as LifeLabs and Dynacare. If you are unsure whether you qualify, a family physician or a telehealth clinician can review your risk factors and order the test if appropriate.
Sources
- 2010 Clinical Practice Guidelines for the Diagnosis and Management of Osteoporosis in Canada — CMAJ
- Pharmacological Management of Osteoporosis in Postmenopausal Women: An Endocrine Society Clinical Practice Guideline
- Osteoporosis Due to Hormone Imbalance: An Overview of the Effects of Estrogen Deficiency and Glucocorticoid Overuse on Bone Turnover — PMC / Int J Mol Sci
- Osteoporosis in Females — StatPearls, NCBI Bookshelf
- Osteoporosis: Symptoms, Causes, and Overview — NIAMS (NIH)
- Osteoporosis Canada — Patient and Clinician Resources