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.