CHRONIC DIPHENYLHYDANTOIN THERAPY DOES NOT REDUCE PLASMA 25‐HYDROXY‐VITAMIN D

Abstract

A randomized controlled study was performed to investigate the effect of 2 years’monitored diphenylhydantoin (DPH) therapy on plasma 25‐hydroxyvitamin D (25‐OHD) in nonepileptic, non‐institutionalized subjects. Mean ± SEM plasma 25‐OHD of 18 DPH‐treated subjects at the end of 2 years’drug treatment was 59 ± 8 nmol/l (23.6 ± 3.2 ng/ml), which was not decreased compared to that of eighteen control subjects (54±8 nmol/l, 21.6±3.2 ng/ml). In addition, mean plasma 25‐OHD had not changed 1 month after ceasing DPH. The treated group had a higher mean serum alkaline phosphatase (SAP) during DPH treatment, attributable to hepatic enzyme induction. It is concluded that therapeutic doses of DPH without..