Vitamin D for Glucocorticoid Users
Chronic glucocorticoid therapy — prednisone for rheumatoid arthritis, lupus, polymyalgia rheumatica, inflammatory bowel disease, transplant — causes accelerated bone loss and fractures. Glucocorticoid-induced osteoporosis (GIOP) is preventable with calcium plus vitamin D, plus bisphosphonate or denosumab in higher-risk patients.
The mechanism
Glucocorticoids reduce calcium absorption from the gut, increase urinary calcium loss, inhibit osteoblast function, and increase osteoclast activity. Bone loss is fastest in the first 3-6 months of therapy — ~5-10% of trabecular bone can be lost in the first year at prednisone doses of 7.5-10+ mg/day.
ACR 2022 GIOP guidance
- All adults on ≥ 2.5 mg/day prednisone for ≥ 3 months: calcium 1,000-1,200 mg/day (food + supplement) and vitamin D 600-800 IU/day.
- Higher fracture risk (older age, low bone density, prior fracture, higher steroid dose): add bisphosphonate (alendronate, risedronate, zoledronic acid) or denosumab.
- Postmenopausal women and older men on ≥ 5 mg/day prednisone: DEXA screening and consideration of anti-resorptive.
- Young adults: dosing more individualised; still test 25(OH)D and correct deficiency.
Dosing detail
- Test baseline 25(OH)D at glucocorticoid initiation.
- Correct to ≥ 30 ng/mL: 2,000-4,000 IU/day cholecalciferol for correction.
- Maintenance 800-1,000 IU/day for long-term steroid users.
- Calcium 1,000-1,200 mg/day from food preferentially; supplement to close the gap.
- DEXA at baseline and every 1-2 years on chronic steroids.
Inhaled and topical steroids
Inhaled corticosteroids at low-to-moderate asthma/COPD doses have modest systemic effect on bone. High-dose inhaled (e.g., fluticasone 500+ µg/day) and long-term topical use over large areas do have measurable systemic effects. Standard vitamin D + calcium remains reasonable general care.
Withdrawal considerations
Bone density gradually recovers after glucocorticoid discontinuation, but fracture risk remains elevated for years. Continue vitamin D + calcium and the anti-resorptive therapy per your rheumatology / endocrinology plan even during dose tapering.