Do anticonvulsant drugs commonly induce osteomalacia?

Twenty adult epileptic out-patients who had received anticonvulsant therapy for a mean duration of 15 years were assessed for clinical, biochemical, radioisotopic and bone biopsy evidence of osteomalacia. Occasional biochemical abnormalities were demonstrated but no individual subject was found to have osteomalacia. There is increasing evidence to cast doubt on the existence of a strong relationship between anticonvulsant drugs and osteomalacia. This evidence is reviewed and it is concluded that in the presence of adequate sunlight exposure anticonvulsant therapy alone is most unlikely to lead to osteomalacia in adults.