The effect of vitamin D supplementation on seizure frequency, mental health parameters, metabolic and genetic profiles in patients with epilepsy

The aim of this study is to determine the effects of vitamin D supplementation on seizure frequency, mental health parameters, metabolic and genetic profiles in patients with epilepsy.

Study design: Randomized double-blind placebo-controlled trial. Randomization will be done by the use of computer-generated random numbers. Patients will be assigned into two groups to receive vitamin D supplement (n=45) or placebo (n=45).

Among patients with epilepsy referred to Shahid Beheshti Clinic affiliated to Kashan University of Medical Sciences, 90 patients will be selected according to inclusion and exclusion criteria. Participants, investigators or the assessors of the outcomes are unaware of the study groups. Supplements and placebos are similar in shape and size. Fasting blood samples will be taken at baseline and 12 weeks after the intervention. At the beginning and the end of the intervention: 12 weeks.

Inclusion criteria: Patients aged 9 to 18 years and diagnosed with epilepsy; Individuals have vitamin D insufficiency and deficiency. Non-inclusion criteria: History of liver diseases; History of renal insufficiency; metabolic disorders; infectious diseases; autoimmune diseases; Taking vitamin D and other antioxidant supplements in the last 3 months and during the study.

Intervention group: 50000 IU vitamin D (Zahravi, Tabriz, Iran), every 2 weeks, for 12 weeks orally. Control group: Placebo (Barij Essence, Kashan, Iran), every 2 weeks, for 12 weeks orally.

Outcomes: Beck depression inventory and the frequency of seizures (primary outcomes) and biomarkers of inflammation; oxidative stress; lipid profiles; markers of insulin metabolism; gene expression related to inflammation and insulin (secondary outcomes) will be quantified at study baseline and end-of-trial.

To decrease potential confounding effects, all participants will have stratified randomization according to gender (male vs. female), type of seizures (tonic-clonic vs. partial) and circulating levels of vitamin D at baseline (<15 vs. 15-29.9 ng/mL). Then, participants in each block will be randomly allocated into two treatment groups to take either supplements or placebo. Randomization will be done by the use of computer software.

Randomization and allocation will be concealed from the researchers and participants until the final analyses are completed. Another person at the neurology clinic, who is not involved in the trial and not aware of random sequences, will be assigned the participants to the numbered bottles of supplements.