Osteoporosis is commonly thought of as an older person's condition. But Canadians in their 20s, 30s, and 40s can have low bone density — or be on a trajectory toward fractures that could have been prevented. Here's what young Canadians need to know.
The window for building bone density closes in your late 20s. By around age 30, you've reached your "peak bone mass" — the maximum density your skeleton will ever have. Everything from that point is maintenance and gradual decline. If peak bone mass was lower than it should have been (due to nutrition, hormones, illness, or activity level during childhood and young adulthood), you start the maintenance phase from a lower baseline.
Additionally, several conditions common in young women directly accelerate bone loss, creating osteopenia or osteoporosis well before menopause.
The female athlete triad describes the interaction between three interrelated conditions: low energy availability (eating too little relative to energy expenditure), menstrual dysfunction (irregular or absent periods), and low bone density. The broader concept, "Relative Energy Deficiency in Sport" (RED-S), also applies to male athletes.
When a young woman exercises heavily but doesn't eat enough to fuel both her sport and her body's normal functions, her reproductive hormone levels drop. Without adequate estrogen, bone density suffers. Elite runners, gymnasts, dancers, rowers, and figure skaters have elevated rates of stress fractures and lower bone density than their sedentary peers.
Anorexia nervosa has the highest mortality rate of any psychiatric disorder in Canada, and bone loss is one of the most serious medical complications. Low body weight, low estrogen, malnutrition, and high cortisol all converge to devastate bone density. Bone loss in anorexia can be rapid and severe — and unlike many other effects of the illness, bone density doesn't always fully recover even after weight restoration.
Bulimia nervosa also carries bone health risks, though typically less severe than anorexia, due to chronic low nutrient status and hormonal disruption.
Independent of eating disorders, being underweight (BMI under 18.5) is associated with lower bone density. Lower body weight means less mechanical loading on the skeleton (less stimulus for bone formation) and often lower estrogen levels. This is one of the few areas where higher body weight is actually protective for bone health.
The relationship between hormonal contraceptives and bone health is nuanced. Combined oral contraceptives (estrogen + progestin) generally maintain bone density in most women. However:
POI (previously called premature ovarian failure) means the ovaries stop functioning normally before age 40, leading to very low estrogen. Women with POI have significantly elevated lifetime fracture risk and should be on estrogen replacement therapy until at least the average age of menopause (51) for bone protection. See our menopause and bone health guide for more.
Many of the conditions that cause secondary osteoporosis at any age are common in young adults: celiac disease, Crohn's disease, Type 1 diabetes, rheumatoid arthritis, and corticosteroid use for conditions like asthma or IBD. See our complete guide to secondary osteoporosis.
DEXA scan T-scores were designed for postmenopausal women and are not the right benchmark for younger adults. For premenopausal women, a different measurement — the Z-score — should be used instead. The Z-score compares your bone density to people of your same age and sex.
A Z-score below −2.0 is considered "below the expected range for age" and warrants investigation. T-scores below −2.5 technically indicate osteoporosis by density alone, but the clinical significance is different in a 30-year-old than a 65-year-old.
This is a common frustration: you're young, you have risk factors, and your doctor tells you provincial coverage requires you to be older. Here's the reality:
| Province | Covered Under 50 If... |
|---|---|
| Ontario | Fragility fracture, corticosteroid use, hypogonadism, malabsorption diseases, or eating disorder with clinical concern |
| British Columbia | Fragility fracture, secondary causes, or physician-documented significant risk |
| Alberta | Secondary causes, long-term corticosteroid use, fragility fracture |
| Quebec | Secondary causes, fragility fracture, eating disorders with physician referral |
| Other provinces | Generally similar criteria — fragility fracture, secondary causes, significant risk factors |
If your doctor has identified risk factors, they can document them in the referral to obtain coverage. If you're paying privately, DEXA scans at private imaging clinics typically cost $100–$200 in most Canadian cities.
Treatment of osteoporosis in premenopausal women requires a different approach than in postmenopausal women:
Bisphosphonate therapy may be considered in young adults with severe bone loss or multiple fragility fractures when no other treatment is working, with careful discussion of pregnancy plans. Denosumab is generally not used in premenopausal women due to its rebound effect. These decisions require specialist involvement.
For young Canadians under 30, the window for building peak bone mass is still open. Strategies that make the biggest difference:
For young adults with suspected bone density problems: