The effects of long-term anticonvulsant drug therapy on vitamin D metabolites and mineral homeostasis in pregnant epileptic women and their newborns.

Serum concentrations of 25-hydroxyvitamin D (25(OH)D), (24,25(OH)2D), 1,25-dihydroxyvitamin D (1,25(OH)2D), total calcium, protein, phosphorus, magnesium and alkaline phosphatase (ALP) were measured in 21 epileptic and 20 healthy control mothers. Serum samples were collected in the third trimester of pregnancy and at delivery, when also mixed blood from the umbilical cord was drawn. 25(OH)D concentrations were similar in both groups and different anticonvulsant drugs had no effects on values. There were small alterations in dihydroxylated vitamin D metabolites. 24,25(OH)2D values were decreased and 1,25(OH)2D concentrations increased. The difference was significant (p less than 0.05) in maternal 1,25(OH)2D values at delivery. Other alterations were statistically almost significant. There was no difference between the diphenylhydantoin and carbamazepine groups. Calcium concentrations were significantly higher in the control than in the epileptic group (in the third trimester p less than 0.01 and at delivery p less than 0.001). Magnesium and phosphorus concentrations were similar in both groups. ALP concentrations were higher in epileptics than in control subjects. Though there were differences in maternal values between epileptics and controls, the fetal concentrations of the analyzed parameters were quite similar in both groups, except for ALP values, which were significantly higher (p less than 0.05) in epileptics than in controls. It was found only slight alterations in vitamin D metabolites. These changes cannot explain hypocalcaemia and osteopenia found often in these patients.