Osteoporosis — NZ Condition Guide | KiwiMeds

What is Osteoporosis?

Osteoporosis is a condition where bones become weak and brittle, increasing the risk of fractures (broken bones). The word osteoporosis means “porous bones.” Osteoporosis is common — around 100,000 New Zealanders have osteoporosis and around 1 in 3 women and 1 in 5 men over 50 will have an osteoporotic fracture in their lifetime. It is often called a “silent disease” because there are usually no symptoms until a fracture occurs. Hip fractures from osteoporosis are a leading cause of hospitalisation, disability, and death in older New Zealanders.

Symptoms

Osteoporosis has no symptoms until a fracture occurs. Warning signs that may suggest osteoporosis include a fracture from a minor fall or bump (fragility fracture), loss of height over time, and a stooped posture (kyphosis — caused by compression fractures of the spine). Back pain can occur from vertebral (spine) fractures.

Causes and Risk Factors

Osteoporosis occurs when bone is lost faster than it is replaced. Peak bone mass is reached in your late 20s — after that, bone loss gradually exceeds gain. Risk factors include female sex (oestrogen protects bone, so risk rises after menopause), age over 50, family history of osteoporosis, previous fracture, low body weight, smoking, excessive alcohol, low calcium and vitamin D intake, physical inactivity, long-term use of corticosteroids, and some medical conditions (coeliac disease, rheumatoid arthritis, hyperthyroidism).

Diagnosis

Osteoporosis is diagnosed with a DXA (dual-energy X-ray absorptiometry) scan — a low-radiation X-ray that measures bone mineral density (BMD) at the hip and spine. Results are expressed as a T-score. A T-score of -2.5 or below indicates osteoporosis. Your GP will assess your fracture risk using the FRAX tool, which takes into account multiple risk factors. In NZ, DXA scans are funded for people who meet certain criteria.

Treatment in New Zealand

Treatment includes adequate calcium (1000–1200mg/day from food and supplements) and vitamin D (most older adults need a supplement), regular weight-bearing and resistance exercise, fall prevention strategies, and medications if fracture risk is high. Pharmac funds bisphosphonates — alendronate (weekly tablet) and zoledronate (yearly intravenous infusion) — as first-line treatments. Denosumab (Prolia) is funded for people who cannot tolerate bisphosphonates. Hormone replacement therapy (HRT) is an option for postmenopausal women.

NZ-Specific Information

Pharmac funds alendronate, zoledronate, and denosumab for eligible patients. Vitamin D supplementation is not routinely funded but is inexpensive. The Osteoporosis New Zealand website (osteoporosis.org.nz) provides excellent NZ-specific resources. Falls prevention programmes are widely available through Te Whatu Ora — ask your GP about referral.

Frequently Asked Questions

Can osteoporosis be reversed? Bone density can be improved with treatment, but full reversal to normal density is rarely achieved. The goal is to prevent fractures. How long do I take bisphosphonates? Usually 3–5 years, then reassessed. A “drug holiday” may be recommended. Do men get osteoporosis? Yes — it is less common but significant. Men account for 30% of osteoporotic fractures.

Supplements That May Support Management

⚠️ Important: The supplements listed below have varying levels of clinical evidence. They are not a substitute for prescribed medications and should only be considered as adjunctive support under the guidance of a qualified healthcare professional. Always inform your GP or pharmacist before commencing any supplement, as interactions with prescribed medicines are possible.

• Calcium — Adequate calcium is foundational to bone mineral density maintenance. In those unable to meet the recommended daily intake (1000–1200 mg) through diet alone, supplementation (typically 500–600 mg/day in divided doses) is advised. Calcium citrate is preferred over calcium carbonate in those on proton pump inhibitors or with reduced gastric acid. Evidence suggests supplements above dietary needs provide limited additional benefit and may carry cardiovascular risk — dietary sources are strongly preferred.
• Vitamin D — Vitamin D is essential for calcium absorption from the gastrointestinal tract and calcium regulation in bone metabolism. Supplementation of 800–2000 IU/day is recommended for people with osteoporosis or at risk, with higher doses under medical supervision. Vitamin D levels should be confirmed via serum 25-OH vitamin D testing.
• Vitamin K2 (MK-7) — Vitamin K2 activates osteocalcin, a bone matrix protein critical for calcium incorporation into bone mineral. Several trials, primarily Japanese, demonstrate fracture risk reduction with MK-7 supplementation (180–360 mcg/day). Evidence is strongest in combination with vitamin D.
• Magnesium — Approximately 60% of the body’s magnesium is stored in bone. Adequate magnesium supports bone density and enhances the activity of vitamin D. Supplementation at 200–400 mg/day is considered adjunctive in people with dietary inadequacy.
• Collagen Peptides — Type 1 collagen comprises approximately 90% of bone organic matrix. Specific collagen peptide supplementation (5–10 g/day) has shown improvements in bone turnover markers in randomised trials, representing a promising adjunct to pharmacological therapy.

Relevant Vaccinations

Individuals living with osteoporosis may benefit from the following vaccinations. Please discuss your vaccination status with your GP or practice nurse, as eligibility and funding through the New Zealand National Immunisation Schedule may apply.

• Influenza (annual) — Influenza is funded and recommended for those aged 65 and over — the primary demographic affected by osteoporosis. Illness-related immobility also increases fracture risk.
• Shingles (Zoster, Shingrix) — Herpes zoster (shingles) can cause prolonged immobility and pain that increases fall and fracture risk in elderly people with osteoporosis. The Shingrix vaccine is recommended for adults over 50.
• Pneumococcal — Pneumonia-related hospitalisation significantly increases the risk of immobility-related bone loss and fractures. Pneumococcal vaccination is recommended for adults 65 and older.

Dietary Guidance

Evidence-based dietary modifications play a meaningful role in the management of osteoporosis. The following foods are generally recommended as part of a balanced, condition-appropriate diet. A referral to a registered dietitian may be beneficial for personalised nutritional planning.

• Dairy products (milk, yoghurt, cheese) — The most bioavailable dietary source of calcium. Low-fat dairy options provide approximately 300 mg calcium per serving. Three servings per day meets recommended calcium intake for most adults.
• Calcium-fortified plant milks (soy, almond, oat milk) — A suitable dairy alternative for people avoiding dairy, provided the product is fortified with calcium. Check labels — fortified soy milk provides comparable calcium to dairy milk.
• Canned fish with bones (sardines, salmon) — An excellent source of both calcium and vitamin D. Sardines with bones provide approximately 350 mg calcium per 100 g serving, along with omega-3 fatty acids.
• Dark leafy greens (bok choy, kale, broccoli) — Provide bioavailable calcium alongside vitamin K1, which is converted to K2 by gut bacteria. Spinach and silverbeet are high in calcium but also high in oxalates which reduce absorption.
• Fortified foods (cereals, orange juice) — Some cereals and juices are fortified with both calcium and vitamin D, supporting bone health when dairy intake is limited.
• Limit alcohol and smoking — Alcohol consumption above moderate levels (>2 standard drinks/day) and tobacco smoking are independent risk factors for reduced bone mineral density and increased fracture risk, and should be minimised.

Related Conditions & Medications

Related medications: Alendronate, Calcium supplements. Related conditions: Hypothyroidism.