Actions of Vitamins D2 and D3 and 25-OHD3 in Anticonvulsant Osteomalacia

Abstract

In 54 epileptic outpatients treated for at least one year with anticonvulsants the bone mineral content (B.M.C.), an estimate of total body calcium, and serum calcium were measured before and during treatment with three doses of cholecalciferol (vitamin D3; 200, 100, and 50 [ig daily) and 25-hydroxy cholecalciferol (25-OHD3; 40, 20, and 10 (ig daily) for 12 weeks. The results, when compared with the effects of calciferol (vitamin D2; 200,100, and 50 μg daily) in 40 epileptic outpatients, showed different actions in anticonvulsant osteomalacia of vitamin D2on the one hand and vitamin D3and 25-OHD3on the other. In the patients who received vitamin D2an increase in B.M.C. was found whereas serum calcium was unchanged. The patients who received vitamin D3or 25-OHD3showed an increase in serum calcium but unchanged values of B.M.C. The results suggest that liver enzyme induction cannot alone explain anticonvulsant osteomalacia. © 1975, British Medical Journal Publishing Group. All rights reserved.