High-Dose Treatment With Vitamin A Analogues and Risk of Fractures

OBJECTIVE: To study fracture risk associated with use of systemic vitamin A analogue (isotretinoin and acitretin) treatment. DESIGN: Case-control study. SETTING: Nationwide registry. PARTICIPANTS: A total of 124 655 patients with fractures (cases) and 373 962 age- and sex-matched controls. Main Outcome Measure Incidence of fractures in patients with and without exposure to systemic vitamin A analogues. Confounder control was performed for social variables, contacts with hospitals and general practitioners, alcoholism, and a number of other variables known to potentially affect fracture risk, including use of systemic, intramuscular, and topical corticosteroids and antiepileptic drugs and comorbid conditions. RESULTS: No trend in risk of any fracture or of hip, forearm, or spine fractures was present with increasing doses or durations of treatment with vitamin A analogues. Subdividing vitamin A analogues into isotretinoin and acitretin did not change the results. CONCLUSION: Risk of fracture is not associated with vitamin A analogue treatment.