[Disorders of calcium metabolism and ossification caused by anticonvulsants]

Disturbances of Calcium-metabolism and of ossification are well known and well documented side-effects of anticonvulsant drugs since the first description in 1967. Elevated alkaline phosphatase and hypocalcemia till generalised osteoporosis and vitamin-D-sensitive rickets can be seen. The primary cause of these dose-related disturbances is an accelerated elimination of vitamin D because of induction of microsomal enzymes in the liver by anticonvulsant drugs; a suboptimal vitamin-D-intake and reduced sunlight exposure in institutionalised patients are often combined causative factors. In all patients treated with anticonvulsant drugs a sufficient supplementation with vitamin D is necessary.