Possible Interaction: Anticonvulsants and Vitamin D

“On the other hand, the administration of vitamin D in a daily dose of 4,000 IU for a period of two months hampered the appearance, or restored already existing changes of latent rickets, in children receiving anticonvulsive medication.”

“The need for simultaneous daily administration of supplements of vitamin D in subjects receiving anticonvulsive drugs is stressed.”

“The frequency of epileptic seizures was observed in a controlled therapeutic trial on 23 epileptic inpatients before and after treatment with vitamin D2 or placebo in addition to anticonvulsant drugs.”

“Hepatic enzyme induction by certain anticonvulsant medications appears to contribute to increased metabolism of 25-hydroxyvitamin D to inactive metabolites, which results in metabolic bone disease.”

“This review also identified a randomized controlled trial whose results suggest that supplementation with high-dose vitamin D may be associated with increased bone mineral density in patients taking anticonvulsant medications.”

“ 25(OH)D3 levels were lower in patients who had taken anticonvulsants for more than 2 years as compared to those who had taken them for less than 2 years (p=0.03).”

“Serum 25-hydroxyvitamin D was significantly lower among patients treated with anticonvulsant drugs that induce the metabolism of vitamin D (30 [21-51] nmol/l) than among the remaining patients (51 [40-65] nmol/l) and controls.”

“This tendency is more prominent in patients treated with anticonvulsant drugs that induce the metabolism of 25-hydroxyvitamin D. ”

“Therefore, liver diseases, renal failure, and use of anticonvulsant drugs may affect the levels of vitamin D (7).”

“Hypovitaminosis D is highly prevalent in SLE as a result of avoidance of sunshine, photoprotection, renal insufficiency and the use of medications such as glucocorticoids, anticonvulsants , antimalarials and the calcineurin inhibitors, which alter the metabolism of vitamin D or downregulate the functions of the vitamin D receptor.”

“Supplementation with folic acid, vitamin B6, biotin, vitamin D , and L-carnitine may be needed to prevent or treat deficiencies resulting from the use of anticonvulsant drugs.”

“ Anticonvulsant medication may … of vitamin D , and vitamin D intake from diet and sunlight exposure may be reduced in this population, increasing the risk of fracture.3 Assessing … in children who are immobilized with CP should be a routine event with appropriate supplements being given to all affected children.”

“ Anticonvulsants impair bone metabolism by induction of hepatic microsomal enzymes resulting in increased catabolism of 25(OH)vitamin D3 and perhaps also through inhibition of intestinal transport of calcium.”