What is the recommended calcium and vitamin D supplementation regimen for patients on long-term steroid therapy to prevent osteoporosis?

Calcium and Vitamin D Supplementation for Long-Term Steroid Use

All patients starting or receiving corticosteroid therapy should receive 800-1000 mg of calcium daily (from diet plus supplements) and 800 IU of vitamin D daily to prevent corticosteroid-induced bone loss. 1

Core Supplementation Regimen

The British Society of Gastroenterology provides strong recommendations (GRADE: strong recommendation, very low-quality evidence) for the following regimen 1:

• Calcium: 800-1000 mg/day (can be achieved through dietary intake plus supplementation) 1
• Vitamin D: 800 IU/day (standard maintenance dose) 1
• If vitamin D deficient: Treat with 50,000 IU weekly for 6 weeks initially, then maintain with 800 IU daily 1

This recommendation is echoed by the European Association for the Study of the Liver (EASL), which states that vitamin D supplementation and adequate calcium intake should be recommended to all patients receiving steroid therapy 1

Mechanism and Rationale

Corticosteroids cause bone loss through multiple mechanisms 1:

• Reduce calcium absorption from the gut
• Increase urinary calcium losses
• Lead to secondary hyperparathyroidism resulting in bone resorption
• Suppress osteoblastic activity

A Cochrane review of five trials confirmed that calcium and vitamin D supplementation for all patients treated with steroids prevented bone loss from the lumbar spine and forearm 1

Risk Assessment and Additional Interventions

Immediate Assessment at Steroid Initiation

All patients starting corticosteroids should be assessed for osteoporosis risk factors 1:

High-risk criteria requiring bone densitometry (DEXA scan):

• Previous fragility fracture 1
• Prolonged steroid use (>3 months) or repeated courses 1
• Age ≥40 years with risk factors 1
• High FRAX score (≥20% major fracture risk or ≥3% hip fracture risk) 1

Additional risk factors to assess and modify 1:

• Uncontrolled inflammation
• Weight loss and malabsorption
• Lack of physical activity, especially weight-bearing exercise
• Alcohol excess
• Smoking

Bisphosphonate Therapy

Patients at high risk should be started on bisphosphonate therapy at the onset of corticosteroid therapy (GRADE: strong recommendation, high-quality evidence), after ensuring adequate calcium intake and supplementing vitamin D 1. The evidence supports alendronate as particularly effective when osteoporosis is present 1.

Practical Implementation

Calcium Formulation Considerations

• Calcium citrate may be preferred over calcium carbonate, especially for patients taking proton pump inhibitors, as it doesn't require gastric acid for absorption 2
• Take calcium in divided doses of no more than 600 mg for optimal absorption 2
• Calculate total calcium intake from diet plus supplements to reach 800-1000 mg/day, not exceeding the recommended dose 2

Vitamin D Dosing Specifics

For patients with documented vitamin D deficiency (<20 ng/mL) 2:

1. Initial correction: 50,000 IU weekly for 6-8 weeks 1, 2
2. Maintenance: 800-1,000 IU daily 2

Target serum 25-hydroxyvitamin D level: At least 20 ng/mL for bone health, with some evidence supporting 30 ng/mL for optimal fracture prevention 2

Monitoring Requirements

During calcium and vitamin D supplementation 2:

• Measure serum calcium and phosphorus at least every 3 months
• Measure 25-hydroxyvitamin D levels after 3 months to confirm adequate supplementation
• Bone mineral density evaluation every 1-2 years

DEXA scan timing 1:

• At presentation/initiation of steroids
• Re-test in 3-5 years based on risk
• Consider re-assessment after 2 years if on treatment 2

Essential Lifestyle Modifications

All patients should receive counseling on 1, 2:

• Regular weight-bearing and muscle-building exercise (weight training, running)
• Smoking cessation
• Reduce excess alcohol intake
• Limit excessive caffeine

Important Caveats

Cardiovascular Considerations

Calcium supplementation may increase cardiovascular risk, particularly if not accompanied by vitamin D supplementation 1. However, the National Osteoporosis Foundation concluded with moderate-quality evidence that calcium with or without vitamin D has no relationship to cardiovascular disease in generally healthy adults 2.

Dental Health

Current UK guidance recommends dental examination with preventative dentistry in those with dental disease or risk factors (corticosteroid use, smoking), with maintenance of good oral hygiene and regular check-ups 1.

Hypercalciuria Risk

Monitor for hypercalciuria, especially in patients receiving calcium and vitamin D therapy 3, 4. There is no risk of hypercalcemia except in patients with sarcoidosis, where calcium levels should be monitored 2.

FRAX Score Limitations

FRAX assumes an average dose of 2.5-7.5 mg/day prednisolone equivalent and does not discriminate past versus current corticosteroid use 1. Adjust risk assessment accordingly:

• Low dose (<2.5 mg/day): Multiply calculated risk by 0.65-0.8 1
• High dose (>7.5 mg/day): Multiply calculated risk by 1.15-1.2 1

Duration of Supplementation

Calcium and vitamin D supplementation should continue for the entire duration of corticosteroid therapy 2. For patients who discontinue glucocorticoids but remain at moderate, high, or very high risk of fracture, continue osteoporosis therapy including supplementation 2. The American Gastroenterological Association recommends a minimum of five years of supplementation with periodic bone mineral density evaluations 2.