Evaluating the effect of calcifediol supplementation on seizure frequency in people with drug-resistant epilepsy

: The well-known neuroprotective role and involvement of vitamin D in the function of the central nervous system has raised the speculation about the possible antiseizure effect of vitamin D supplementation. This issue is crucial when considering people with epilepsy (PWE), who frequently display vitamin D deficiency, but nowadays data are still unconclusive. In our study, we enrolled 25 adult patients affected by drug-resistant epilepsy and hypovitaminosis D to test the effect of Calcifediol on seizure frequency after 6 months of supplementation. Our findings evidenced that Calcifediol administration completely restored 25-hydroxy vitamin D (25-OHD) and intact parathyroid hormone (iPTH) serum values (p < 0.001 for both) without significant changes of median seizure frequency (-6.1%). Anyway, we observed some rate of PWE responders (32%) to Calcifediol supplementation. Further randomized controlled trials with larger subjects 'samples will be needed to verify the possible antiseizure effect of vitamin D.