Initial and maintenance dose of vitamin D2 in the treatment of anticonvulsant osteomalacia.

Abstract

Bone mineral content (BMC), serum calcium and serum alkaline phosphatase levels were measured in 40 epileptics on long-term phenytoin treatment, before and during treatment with vitamin D2 Initially the patients were divided into 3 groups, who received 2000, 4000, and 8000 international units daily for 105 days. Hereafter the 27 patients on the two higher doses were subdivided into two groups, who for a further 150 days received either 1000 I.U. or 200 I.U. daily. During the whole study the biochemical parameters were unaffected by the vitamin D treatment. With all 3 doses an initial increase in BMC (corresponding to a positive calcium balance) was observed, which was highest with 4000 I.U. daily. With this dose the mean BMC value was normalized. In the following maintenance dose period an estimated calcium balance close to zero was seen with 1000 I.U. daily, whereas the patients on 200 I.U. daily showed a negative calcium balance, as their BMC values returned to the initial figures. It is a cost-benefit problem whether it is advisable to give prophylactic vita-min D treatment to epileptic patients. To elucidate this problem a controlled therapeutic trial on a large scale would be needed, so planned as to clarify the clinical benefit of such treatment.