Calcium Supplementation for Osteoporosis
Patients with osteoporosis should take 1200 mg of elemental calcium daily if they are postmenopausal women or men over 70 years, and 1000 mg daily if they are premenopausal adults (19-50 years). 1
Recommended Daily Calcium Intake
The recommended daily calcium intake varies based on age and sex:
- Postmenopausal women: 1200 mg daily 1
- Men over 70 years: 1200 mg daily 1
- Premenopausal adults (19-50 years): 1000 mg daily 1
- Younger men and premenopausal women: 1000 mg/day 2
- Men and women over age 50: up to 1500 mg/day 2
Sources of Calcium
- Dietary sources should be prioritized over supplements
- Aim for approximately 300 mg from non-dairy sources and 740-900 mg from dairy products 1
- Calcium supplements should be considered adjunctive treatment when dietary intake is insufficient 3
Calcium Supplement Types
Different calcium supplements contain varying amounts of elemental calcium:
- Calcium carbonate: 40% elemental calcium - most cost-effective option 1
- Calcium citrate: 21% elemental calcium - better absorbed without food 1
- Calcium acetate: 25% elemental calcium 1
- Calcium lactate: 13% elemental calcium 1
- Calcium gluconate: 9% elemental calcium 1
Administration Guidelines
- Take calcium in divided doses of ≤500 mg elemental calcium to improve absorption 1, 4
- A divided dose regimen (with meals and at bedtime) results in substantially greater absorption than once-daily dosing 4
- Calcium carbonate should be taken with meals to ensure optimal absorption 1, 5
- Calcium citrate can be taken without food and is preferred for individuals taking acid-reducing medications 1, 5
- Total calcium intake (diet plus supplements) should not exceed 2000 mg/day 1, 6
Important Considerations
- Always pair calcium with adequate vitamin D supplementation (800-1000 IU daily) for optimal absorption 1
- High-dose vitamin D supplementation (≥800 IU/day) reduces hip fracture risk by 30% and nonvertebral fracture risk by 14% in persons 65 years or older 1
- Vitamin D insufficiency (levels below 30 ng/mL) is common in patients with osteoporosis 1
- Target vitamin D level should be ≥30 ng/mL, with an optimal range between 30-60 ng/mL 1
Potential Side Effects
- Common side effects include constipation, bloating, and gas 1
- Less common but serious side effects include kidney stones (increased risk with supplements but not with dietary calcium) 1
- Some studies suggest potential cardiovascular risk with high calcium intake, though evidence remains inconsistent 1
Clinical Pearls
- Calcium supplementation alone is not sufficient for treating osteoporosis but forms the foundation of both prevention and treatment 7
- All drug studies demonstrating reduction in osteoporotic fracture risk included calcium and vitamin D supplementation 7
- Regular weight-bearing exercise (30 minutes daily) should be recommended alongside calcium supplementation 1
- Fall prevention measures are important to reduce fracture risk 1
- Bone mineral density testing should be done every 1-2 years to monitor treatment efficacy 1